Merge ref '2f3f27bf79ec' from rust-lang/rust

Pull recent changes from https://github.com/rust-lang/rust via Josh.

Upstream ref: 2f3f27bf79ec147fec9d2e7980605307a74067f4
Filtered ref: 82a5eafbafdb98eae68193600732388ae4135756
Upstream diff: https://github.com/rust-lang/rust/compare/a1dbb443527bd126452875eb5d5860c1d001d761...2f3f27bf79ec147fec9d2e7980605307a74067f4

This merge was created using https://github.com/rust-lang/josh-sync.

29 files changed, 248 insertions, 76 deletions

diff --git a/src/doc/favicon.inc b/src/doc/favicon.inc
index 9c330685209..f09498cc095 100644
--- a/src/doc/favicon.inc
+++ b/src/doc/favicon.inc
@@ -1 +1,2 @@
-<link rel="icon" href="https://www.rust-lang.org/favicon.ico">
+<link rel="alternate icon" type="image/png" href="favicon-32x32.png">
+<link rel="icon" type="image/svg+xml" href="favicon.svg">
diff --git a/src/doc/nomicon b/src/doc/nomicon
-Subproject 3ff384320598bbe8d8cfe5cb8f18f78a3a3e6b1
+Subproject 57ed4473660565d9357fcae176b358d7e8724eb
diff --git a/src/doc/redirect.inc b/src/doc/redirect.inc
index 2fb44be0145..1b7d3744b1f 100644
--- a/src/doc/redirect.inc
+++ b/src/doc/redirect.inc
@@ -1,2 +1,3 @@
 <meta name="robots" content="noindex,follow">
-<link rel="icon" href="https://www.rust-lang.org/favicon.ico">
+<link rel="alternate icon" type="image/png" href="../favicon-32x32.png">
+<link rel="icon" type="image/svg+xml" href="../favicon.svg">
diff --git a/src/doc/reference b/src/doc/reference
-Subproject 59b8af811886313577615c2cf0e045f01faed88
+Subproject 89f67b3c1b904cbcd9ed55e443d6fc67c8ca276
diff --git a/src/doc/rust-by-example b/src/doc/rust-by-example
-Subproject adc1f3b9012ad3255eea2054ca30596a953d053
+Subproject ad27f82c18464525c761a4a8db2e01785da59e1
diff --git a/src/doc/rustc-dev-guide/src/building/bootstrapping/writing-tools-in-bootstrap.md b/src/doc/rustc-dev-guide/src/building/bootstrapping/writing-tools-in-bootstrap.md
index 41d0cf8d9fb..c3660e24b15 100644
--- a/src/doc/rustc-dev-guide/src/building/bootstrapping/writing-tools-in-bootstrap.md
+++ b/src/doc/rustc-dev-guide/src/building/bootstrapping/writing-tools-in-bootstrap.md
@@ -11,11 +11,8 @@ There are three types of tools you can write in bootstrap:
   Use this for tools that rely on the locally built std. The output goes into the "stageN-tools" directory.
   This mode is rarely used, mainly for `compiletest` which requires `libtest`.
 
-- **`Mode::ToolRustc`**
-  Use this for tools that depend on both the locally built `rustc` and the target `std`. This is more complex than
-  the other modes because the tool must be built with the same compiler used for `rustc` and placed in the "stageN-tools"
-  directory. When you choose `Mode::ToolRustc`, `ToolBuild` implementation takes care of this automatically.
-  If you need to use the builder’s compiler for something specific, you can get it from `ToolBuildResult`, which is
+- **`Mode::ToolRustcPrivate`**
+  Use this for tools that use the `rustc_private` mechanism, and thus depend on the locally built `rustc` and its rlib artifacts. This is more complex than the other modes because the tool must be built with the same compiler used for `rustc` and placed in the "stageN-tools" directory. When you choose `Mode::ToolRustcPrivate`, `ToolBuild` implementation takes care of this automatically. If you need to use the builder’s compiler for something specific, you can get it from `ToolBuildResult`, which is
   returned by the tool's [`Step`].
 
 Regardless of the tool type you must return `ToolBuildResult` from the tool’s [`Step`] implementation and use `ToolBuild` inside it.
diff --git a/src/doc/rustc-dev-guide/src/tests/adding.md b/src/doc/rustc-dev-guide/src/tests/adding.md
index e5c26bef11d..46b8a1e4cf4 100644
--- a/src/doc/rustc-dev-guide/src/tests/adding.md
+++ b/src/doc/rustc-dev-guide/src/tests/adding.md
@@ -29,6 +29,8 @@ guidelines:
     suites.
   - Need to inspect the resulting binary in some way? Or if all the other test
     suites are too limited for your purposes? Then use `run-make`.
+    - Use `run-make-cargo` if you need to exercise in-tree `cargo` in conjunction
+      with in-tree `rustc`.
   - Check out the [compiletest] chapter for more specialized test suites.
 
 After deciding on which kind of test to add, see [best
diff --git a/src/doc/rustc-dev-guide/src/tests/best-practices.md b/src/doc/rustc-dev-guide/src/tests/best-practices.md
index be00207e3fb..efc626035b7 100644
--- a/src/doc/rustc-dev-guide/src/tests/best-practices.md
+++ b/src/doc/rustc-dev-guide/src/tests/best-practices.md
@@ -83,10 +83,10 @@ related tests.
     - E.g. for an implementation of RFC 2093 specifically, we can group a
       collection of tests under `tests/ui/rfc-2093-infer-outlives/`. For the
       directory name, include what the RFC is about.
-- For the [`run-make`] test suite, each `rmake.rs` must be contained within an
-  immediate subdirectory under `tests/run-make/`. Further nesting is not
-  presently supported. Avoid including issue number in the directory name too,
-  include that info in a comment inside `rmake.rs`.
+- For the [`run-make`]/`run-make-support` test suites, each `rmake.rs` must
+  be contained within an immediate subdirectory under `tests/run-make/` or
+  `tests/run-make-cargo/` respectively. Further nesting is not presently
+  supported. Avoid using _only_ an issue number for the test name as well.
 
 ## Test descriptions
 
diff --git a/src/doc/rustc-dev-guide/src/tests/compiletest.md b/src/doc/rustc-dev-guide/src/tests/compiletest.md
index 4980ed845d6..a4a729935fa 100644
--- a/src/doc/rustc-dev-guide/src/tests/compiletest.md
+++ b/src/doc/rustc-dev-guide/src/tests/compiletest.md
@@ -397,13 +397,19 @@ your test, causing separate files to be generated for 32bit and 64bit systems.
 
 ### `run-make` tests
 
-The tests in [`tests/run-make`] are general-purpose tests using Rust *recipes*,
-which are small programs (`rmake.rs`) allowing arbitrary Rust code such as
-`rustc` invocations, and is supported by a [`run_make_support`] library. Using
-Rust recipes provide the ultimate in flexibility.
+The tests in [`tests/run-make`] and [`tests/run-make-cargo`] are general-purpose
+tests using Rust *recipes*, which are small programs (`rmake.rs`) allowing
+arbitrary Rust code such as `rustc` invocations, and is supported by a
+[`run_make_support`] library. Using Rust recipes provide the ultimate in
+flexibility.
 
 `run-make` tests should be used if no other test suites better suit your needs.
 
+The `run-make-cargo` test suite additionally builds an in-tree `cargo` to support
+use cases that require testing in-tree `cargo` in conjunction with in-tree `rustc`.
+The `run-make` test suite does not have access to in-tree `cargo` (so it can be the
+faster-to-iterate test suite).
+
 #### Using Rust recipes
 
 Each test should be in a separate directory with a `rmake.rs` Rust program,
@@ -476,6 +482,7 @@ Then add a corresponding entry to `"rust-analyzer.linkedProjects"`
 ```
 
 [`tests/run-make`]: https://github.com/rust-lang/rust/tree/master/tests/run-make
+[`tests/run-make-cargo`]: https://github.com/rust-lang/rust/tree/master/tests/run-make-cargo
 [`run_make_support`]: https://github.com/rust-lang/rust/tree/master/src/tools/run-make-support
 
 ### Coverage tests
diff --git a/src/doc/rustc-dev-guide/src/tests/directives.md b/src/doc/rustc-dev-guide/src/tests/directives.md
index f58ee669a25..4be78fac4ec 100644
--- a/src/doc/rustc-dev-guide/src/tests/directives.md
+++ b/src/doc/rustc-dev-guide/src/tests/directives.md
@@ -52,14 +52,14 @@ not be exhaustive. Directives can generally be found by browsing the
 
 See [Building auxiliary crates](compiletest.html#building-auxiliary-crates)
 
-| Directive             | Explanation                                                                                           | Supported test suites | Possible values                               |
-|-----------------------|-------------------------------------------------------------------------------------------------------|-----------------------|-----------------------------------------------|
-| `aux-bin`             | Build a aux binary, made available in `auxiliary/bin` relative to test directory                      | All except `run-make` | Path to auxiliary `.rs` file                  |
-| `aux-build`           | Build a separate crate from the named source file                                                     | All except `run-make` | Path to auxiliary `.rs` file                  |
-| `aux-crate`           | Like `aux-build` but makes available as extern prelude                                                | All except `run-make` | `<extern_prelude_name>=<path/to/aux/file.rs>` |
-| `aux-codegen-backend` | Similar to `aux-build` but pass the compiled dylib to `-Zcodegen-backend` when building the main file | `ui-fulldeps`         | Path to codegen backend file                  |
-| `proc-macro`          | Similar to `aux-build`, but for aux forces host and don't use `-Cprefer-dynamic`[^pm].                | All except `run-make` | Path to auxiliary proc-macro `.rs` file       |
-| `build-aux-docs`      | Build docs for auxiliaries as well.  Note that this only works with `aux-build`, not `aux-crate`.     | All except `run-make` | N/A                                           |
+| Directive             | Explanation                                                                                           | Supported test suites                  | Possible values                               |
+|-----------------------|-------------------------------------------------------------------------------------------------------|----------------------------------------|-----------------------------------------------|
+| `aux-bin`             | Build a aux binary, made available in `auxiliary/bin` relative to test directory                      | All except `run-make`/`run-make-cargo` | Path to auxiliary `.rs` file                  |
+| `aux-build`           | Build a separate crate from the named source file                                                     | All except `run-make`/`run-make-cargo` | Path to auxiliary `.rs` file                  |
+| `aux-crate`           | Like `aux-build` but makes available as extern prelude                                                | All except `run-make`/`run-make-cargo` | `<extern_prelude_name>=<path/to/aux/file.rs>` |
+| `aux-codegen-backend` | Similar to `aux-build` but pass the compiled dylib to `-Zcodegen-backend` when building the main file | `ui-fulldeps`                          | Path to codegen backend file                  |
+| `proc-macro`          | Similar to `aux-build`, but for aux forces host and don't use `-Cprefer-dynamic`[^pm].                | All except `run-make`/`run-make-cargo` | Path to auxiliary proc-macro `.rs` file       |
+| `build-aux-docs`      | Build docs for auxiliaries as well.  Note that this only works with `aux-build`, not `aux-crate`.     | All except `run-make`/`run-make-cargo` | N/A                                           |
 
 [^pm]: please see the [Auxiliary proc-macro section](compiletest.html#auxiliary-proc-macro) in the compiletest chapter for specifics.
 
@@ -243,18 +243,18 @@ ignoring debuggers.
 
 ### Affecting how tests are built
 
-| Directive           | Explanation                                                                                  | Supported test suites     | Possible values                                                                            |
-|---------------------|----------------------------------------------------------------------------------------------|---------------------------|--------------------------------------------------------------------------------------------|
-| `compile-flags`     | Flags passed to `rustc` when building the test or aux file                                   | All except for `run-make` | Any valid `rustc` flags, e.g. `-Awarnings -Dfoo`. Cannot be `-Cincremental` or `--edition` |
-| `edition`           | The edition used to build the test                                                           | All except for `run-make` | Any valid `--edition` value                                                                |
-| `rustc-env`         | Env var to set when running `rustc`                                                          | All except for `run-make` | `<KEY>=<VALUE>`                                                                            |
-| `unset-rustc-env`   | Env var to unset when running `rustc`                                                        | All except for `run-make` | Any env var name                                                                           |
-| `incremental`       | Proper incremental support for tests outside of incremental test suite                       | `ui`, `crashes`           | N/A                                                                                        |
-| `no-prefer-dynamic` | Don't use `-C prefer-dynamic`, don't build as a dylib via a `--crate-type=dylib` preset flag | `ui`, `crashes`           | N/A                                                                                        |
+| Directive           | Explanation                                                                                  | Supported test suites                      | Possible values                                                                            |
+|---------------------|----------------------------------------------------------------------------------------------|--------------------------------------------|--------------------------------------------------------------------------------------------|
+| `compile-flags`     | Flags passed to `rustc` when building the test or aux file                                   | All except for `run-make`/`run-make-cargo` | Any valid `rustc` flags, e.g. `-Awarnings -Dfoo`. Cannot be `-Cincremental` or `--edition` |
+| `edition`           | The edition used to build the test                                                           | All except for `run-make`/`run-make-cargo` | Any valid `--edition` value                                                                |
+| `rustc-env`         | Env var to set when running `rustc`                                                          | All except for `run-make`/`run-make-cargo` | `<KEY>=<VALUE>`                                                                            |
+| `unset-rustc-env`   | Env var to unset when running `rustc`                                                        | All except for `run-make`/`run-make-cargo` | Any env var name                                                                           |
+| `incremental`       | Proper incremental support for tests outside of incremental test suite                       | `ui`, `crashes`                            | N/A                                                                                        |
+| `no-prefer-dynamic` | Don't use `-C prefer-dynamic`, don't build as a dylib via a `--crate-type=dylib` preset flag | `ui`, `crashes`                            | N/A                                                                                        |
 
 <div class="warning">
 
-Tests (outside of `run-make`) that want to use incremental tests not in the
+Tests (outside of `run-make`/`run-make-cargo`) that want to use incremental tests not in the
 incremental test-suite must not pass `-C incremental` via `compile-flags`, and
 must instead use the `//@ incremental` directive.
 
@@ -264,9 +264,9 @@ Consider writing the test as a proper incremental test instead.
 
 ### Rustdoc
 
-| Directive   | Explanation                                                  | Supported test suites                    | Possible values           |
-|-------------|--------------------------------------------------------------|------------------------------------------|---------------------------|
-| `doc-flags` | Flags passed to `rustdoc` when building the test or aux file | `rustdoc`, `rustdoc-js`, `rustdoc-json`  | Any valid `rustdoc` flags |
+| Directive   | Explanation                                                  | Supported test suites                   | Possible values           |
+|-------------|--------------------------------------------------------------|-----------------------------------------|---------------------------|
+| `doc-flags` | Flags passed to `rustdoc` when building the test or aux file | `rustdoc`, `rustdoc-js`, `rustdoc-json` | Any valid `rustdoc` flags |
 
 <!--
 **FIXME(rustdoc)**: what does `check-test-line-numbers-match` do?
diff --git a/src/doc/rustc-dev-guide/src/tests/misc.md b/src/doc/rustc-dev-guide/src/tests/misc.md
index 39f88174879..cc8f501224f 100644
--- a/src/doc/rustc-dev-guide/src/tests/misc.md
+++ b/src/doc/rustc-dev-guide/src/tests/misc.md
@@ -24,8 +24,8 @@ In `ui` tests and other test suites that support `//@ rustc-env`, you can specif
 //@ rustc-env:RUSTC_BOOTSTRAP=-1
 ```
 
-For `run-make` tests, `//@ rustc-env` is not supported. You can do something
-like the following for individual `rustc` invocations.
+For `run-make`/`run-make-cargo` tests, `//@ rustc-env` is not supported. You can do
+something like the following for individual `rustc` invocations.
 
 ```rust,ignore
 use run_make_support::rustc;
diff --git a/src/doc/rustc/src/SUMMARY.md b/src/doc/rustc/src/SUMMARY.md
index b53494ed98d..8e378e53e51 100644
--- a/src/doc/rustc/src/SUMMARY.md
+++ b/src/doc/rustc/src/SUMMARY.md
@@ -49,6 +49,7 @@
     - [aarch64-nintendo-switch-freestanding](platform-support/aarch64-nintendo-switch-freestanding.md)
     - [aarch64-unknown-linux-musl](platform-support/aarch64-unknown-linux-musl.md)
     - [aarch64_be-unknown-none-softfloat](platform-support/aarch64_be-unknown-none-softfloat.md)
+    - [aarch64_be-unknown-linux-musl](platform-support/aarch64_be-unknown-linux-musl.md)
     - [amdgcn-amd-amdhsa](platform-support/amdgcn-amd-amdhsa.md)
     - [armeb-unknown-linux-gnueabi](platform-support/armeb-unknown-linux-gnueabi.md)
     - [arm-none-eabi](platform-support/arm-none-eabi.md)
@@ -106,6 +107,7 @@
     - [riscv32imac-unknown-xous-elf](platform-support/riscv32imac-unknown-xous-elf.md)
     - [riscv64gc-unknown-linux-gnu](platform-support/riscv64gc-unknown-linux-gnu.md)
     - [riscv64gc-unknown-linux-musl](platform-support/riscv64gc-unknown-linux-musl.md)
+    - [riscv64a23-unknown-linux-gnu](platform-support/riscv64a23-unknown-linux-gnu.md)
     - [s390x-unknown-linux-gnu](platform-support/s390x-unknown-linux-gnu.md)
     - [s390x-unknown-linux-musl](platform-support/s390x-unknown-linux-musl.md)
     - [sparc-unknown-none-elf](./platform-support/sparc-unknown-none-elf.md)
@@ -114,6 +116,7 @@
     - [\*-unikraft-linux-musl](platform-support/unikraft-linux-musl.md)
     - [\*-unknown-hermit](platform-support/hermit.md)
     - [\*-unknown-freebsd](platform-support/freebsd.md)
+    - [\*-unknown-managarm-mlibc](platform-support/managarm.md)
     - [\*-unknown-netbsd\*](platform-support/netbsd.md)
     - [\*-unknown-openbsd](platform-support/openbsd.md)
     - [\*-unknown-redox](platform-support/redox.md)
diff --git a/src/doc/rustc/src/command-line-arguments/print-options.md b/src/doc/rustc/src/command-line-arguments/print-options.md
index 1f33e91e5d1..f37b27d88c3 100644
--- a/src/doc/rustc/src/command-line-arguments/print-options.md
+++ b/src/doc/rustc/src/command-line-arguments/print-options.md
@@ -32,7 +32,7 @@ The names of the files created by the `link` emit kind.
 
 ## `sysroot`
 
-Abosulte path to the sysroot.
+Absolute path to the sysroot.
 
 Example (with rustup and the stable toolchain):
 
@@ -184,7 +184,7 @@ Example:
 
 ```bash
 $ rustc --print native-static-libs --crate-type staticlib a.rs
-note: Link against the following native artifacts when linking against this static library. The order and any duplication can be significant on some platforms.
+note: link against the following native artifacts when linking against this static library. The order and any duplication can be significant on some platforms.
 
 note: native-static-libs: -lgcc_s -lutil [REDACTED] -lpthread -lm -ldl -lc
 ```
diff --git a/src/doc/rustc/src/images/image1.png b/src/doc/rustc/src/images/image1.png
index 0da45e56620..3aad6359389 100644
--- a/src/doc/rustc/src/images/image1.png
+++ b/src/doc/rustc/src/images/image1.png
Binary files differdiff --git a/src/doc/rustc/src/images/image2.png b/src/doc/rustc/src/images/image2.png
index a9cf23f8737..085b1c490b8 100644
--- a/src/doc/rustc/src/images/image2.png
+++ b/src/doc/rustc/src/images/image2.png
Binary files differdiff --git a/src/doc/rustc/src/images/image3.png b/src/doc/rustc/src/images/image3.png
index 844a2fe6747..ee332f51055 100644
--- a/src/doc/rustc/src/images/image3.png
+++ b/src/doc/rustc/src/images/image3.png
Binary files differdiff --git a/src/doc/rustc/src/images/llvm-cov-show-01.png b/src/doc/rustc/src/images/llvm-cov-show-01.png
index 35f04594347..ce4dec128b6 100644
--- a/src/doc/rustc/src/images/llvm-cov-show-01.png
+++ b/src/doc/rustc/src/images/llvm-cov-show-01.png
Binary files differdiff --git a/src/doc/rustc/src/platform-support.md b/src/doc/rustc/src/platform-support.md
index 3bf87994297..6c5b48d8c8f 100644
--- a/src/doc/rustc/src/platform-support.md
+++ b/src/doc/rustc/src/platform-support.md
@@ -33,6 +33,7 @@ All tier 1 targets with host tools support the full standard library.
 target | notes
 -------|-------
 [`aarch64-apple-darwin`](platform-support/apple-darwin.md) | ARM64 macOS (11.0+, Big Sur+)
+[`aarch64-pc-windows-msvc`](platform-support/windows-msvc.md) | ARM64 Windows MSVC
 `aarch64-unknown-linux-gnu` | ARM64 Linux (kernel 4.1+, glibc 2.17+)
 [`i686-pc-windows-msvc`](platform-support/windows-msvc.md) | 32-bit MSVC (Windows 10+, Windows Server 2016+, Pentium 4) [^x86_32-floats-return-ABI] [^win32-msvc-alignment]
 `i686-unknown-linux-gnu` | 32-bit Linux (kernel 3.2+, glibc 2.17+, Pentium 4) [^x86_32-floats-return-ABI]
@@ -88,7 +89,6 @@ so Rustup may install the documentation for a similar tier 1 target instead.
 target | notes
 -------|-------
 [`aarch64-pc-windows-gnullvm`](platform-support/windows-gnullvm.md) | ARM64 MinGW (Windows 10+), LLVM ABI
-[`aarch64-pc-windows-msvc`](platform-support/windows-msvc.md) | ARM64 Windows MSVC
 [`aarch64-unknown-linux-musl`](platform-support/aarch64-unknown-linux-musl.md) | ARM64 Linux with musl 1.2.3
 [`aarch64-unknown-linux-ohos`](platform-support/openharmony.md) | ARM64 OpenHarmony
 `arm-unknown-linux-gnueabi` | Armv6 Linux (kernel 3.2+, glibc 2.17)
@@ -103,7 +103,6 @@ target | notes
 [`powerpc64le-unknown-linux-gnu`](platform-support/powerpc64le-unknown-linux-gnu.md) | PPC64LE Linux (kernel 3.10+, glibc 2.17)
 [`powerpc64le-unknown-linux-musl`](platform-support/powerpc64le-unknown-linux-musl.md) | PPC64LE Linux (kernel 4.19+, musl 1.2.3)
 [`riscv64gc-unknown-linux-gnu`](platform-support/riscv64gc-unknown-linux-gnu.md) | RISC-V Linux (kernel 4.20+, glibc 2.29)
-[`riscv64gc-unknown-linux-musl`](platform-support/riscv64gc-unknown-linux-musl.md) | RISC-V Linux (kernel 4.20+, musl 1.2.3)
 [`s390x-unknown-linux-gnu`](platform-support/s390x-unknown-linux-gnu.md) | S390x Linux (kernel 3.2+, glibc 2.17)
 [`x86_64-apple-darwin`](platform-support/apple-darwin.md) | 64-bit macOS (10.12+, Sierra+)
 [`x86_64-pc-windows-gnullvm`](platform-support/windows-gnullvm.md) | 64-bit x86 MinGW (Windows 10+), LLVM ABI
@@ -183,6 +182,7 @@ target | std | notes
 [`riscv32imac-unknown-none-elf`](platform-support/riscv32-unknown-none-elf.md) | * | Bare RISC-V (RV32IMAC ISA)
 [`riscv32imafc-unknown-none-elf`](platform-support/riscv32-unknown-none-elf.md) | * | Bare RISC-V (RV32IMAFC ISA)
 [`riscv32imc-unknown-none-elf`](platform-support/riscv32-unknown-none-elf.md) | * | Bare RISC-V (RV32IMC ISA)
+[`riscv64gc-unknown-linux-musl`](platform-support/riscv64gc-unknown-linux-musl.md) | RISC-V Linux (kernel 4.20+, musl 1.2.3)
 `riscv64gc-unknown-none-elf` | * | Bare RISC-V (RV64IMAFDC ISA)
 `riscv64imac-unknown-none-elf` | * | Bare RISC-V (RV64IMAC ISA)
 `sparc64-unknown-linux-gnu` | ✓ | SPARC Linux (kernel 4.4+, glibc 2.23)
@@ -258,6 +258,7 @@ target | std | host | notes
 [`aarch64-unknown-hermit`](platform-support/hermit.md) | ✓ |  | ARM64 Hermit
 [`aarch64-unknown-illumos`](platform-support/illumos.md) | ✓ | ✓ | ARM64 illumos
 `aarch64-unknown-linux-gnu_ilp32` | ✓ | ✓ | ARM64 Linux (ILP32 ABI)
+[`aarch64-unknown-managarm-mlibc`](platform-support/managarm.md) | ? |   | ARM64 Managarm
 [`aarch64-unknown-netbsd`](platform-support/netbsd.md) | ✓ | ✓ | ARM64 NetBSD
 [`aarch64-unknown-nto-qnx700`](platform-support/nto-qnx.md) | ? |  | ARM64 QNX Neutrino 7.0 RTOS |
 [`aarch64-unknown-nto-qnx710`](platform-support/nto-qnx.md) | ✓ |  | ARM64 QNX Neutrino 7.1 RTOS with default network stack (io-pkt) |
@@ -273,6 +274,7 @@ target | std | host | notes
 [`aarch64_be-unknown-hermit`](platform-support/hermit.md) | ✓ |  | ARM64 Hermit (big-endian)
 `aarch64_be-unknown-linux-gnu` | ✓ | ✓ | ARM64 Linux (big-endian)
 `aarch64_be-unknown-linux-gnu_ilp32` | ✓ | ✓ | ARM64 Linux (big-endian, ILP32 ABI)
+[`aarch64_be-unknown-linux-musl`](platform-support/aarch64_be-unknown-linux-musl.md) | ✓ | ✓ | ARM64 Linux (big-endian) with musl-libc 1.2.5
 [`aarch64_be-unknown-netbsd`](platform-support/netbsd.md) | ✓ | ✓ | ARM64 NetBSD (big-endian)
 [`aarch64_be-unknown-none-softfloat`](platform-support/aarch64_be-unknown-none-softfloat.md) | * |  | Bare big-endian ARM64, softfloat
 [`amdgcn-amd-amdhsa`](platform-support/amdgcn-amd-amdhsa.md) | * |  | `-Ctarget-cpu=gfx...` to specify [the AMD GPU] to compile for
@@ -327,8 +329,8 @@ target | std | host | notes
 [`i686-win7-windows-msvc`](platform-support/win7-windows-msvc.md) | ✓ |   | 32-bit Windows 7 support [^x86_32-floats-return-ABI] [^win32-msvc-alignment]
 [`i686-wrs-vxworks`](platform-support/vxworks.md) | ✓ |  | [^x86_32-floats-return-ABI]
 [`loongarch64-unknown-linux-ohos`](platform-support/openharmony.md) | ✓ |   | LoongArch64 OpenHarmony
-[`loongarch32-unknown-none`](platform-support/loongarch-none.md) | * | LoongArch32 Bare-metal (ILP32D ABI)
-[`loongarch32-unknown-none-softfloat`](platform-support/loongarch-none.md) | * | LoongArch32 Bare-metal (ILP32S ABI)
+[`loongarch32-unknown-none`](platform-support/loongarch-none.md) | * |   | LoongArch32 Bare-metal (ILP32D ABI)
+[`loongarch32-unknown-none-softfloat`](platform-support/loongarch-none.md) | * |   | LoongArch32 Bare-metal (ILP32S ABI)
 [`m68k-unknown-linux-gnu`](platform-support/m68k-unknown-linux-gnu.md) | ? |  | Motorola 680x0 Linux
 [`m68k-unknown-none-elf`](platform-support/m68k-unknown-none-elf.md) |  |  | Motorola 680x0
 `mips-unknown-linux-gnu` | ✓ | ✓ | MIPS Linux (kernel 4.4, glibc 2.23)
@@ -387,10 +389,12 @@ target | std | host | notes
 `riscv64gc-unknown-freebsd` | ? |   | RISC-V FreeBSD
 `riscv64gc-unknown-fuchsia` | ? |   | RISC-V Fuchsia
 [`riscv64gc-unknown-hermit`](platform-support/hermit.md) | ✓ |   | RISC-V Hermit
+[`riscv64gc-unknown-managarm-mlibc`](platform-support/managarm.md) | ? |   | RISC-V Managarm
 [`riscv64gc-unknown-netbsd`](platform-support/netbsd.md) | ✓ | ✓ | RISC-V NetBSD
 [`riscv64gc-unknown-nuttx-elf`](platform-support/nuttx.md) | ✓ |  | RISC-V 64bit with NuttX
 [`riscv64gc-unknown-openbsd`](platform-support/openbsd.md) | ✓ | ✓ | OpenBSD/riscv64
 [`riscv64imac-unknown-nuttx-elf`](platform-support/nuttx.md) | ✓ |  | RISC-V 64bit with NuttX
+[`riscv64a23-unknown-linux-gnu`](platform-support/riscv64a23-unknown-linux-gnu.md) | ✓ | ✓ | RISC-V Linux (kernel 6.8.0+, glibc 2.39)
 [`s390x-unknown-linux-musl`](platform-support/s390x-unknown-linux-musl.md) | ✓ |  | S390x Linux (kernel 3.2, musl 1.2.3)
 `sparc-unknown-linux-gnu` | ✓ |  | 32-bit SPARC Linux
 [`sparc-unknown-none-elf`](./platform-support/sparc-unknown-none-elf.md) | * |  | Bare 32-bit SPARC V7+
@@ -426,6 +430,7 @@ target | std | host | notes
 [`x86_64-unknown-hurd-gnu`](platform-support/hurd.md) | ✓ | ✓ | 64-bit GNU/Hurd
 `x86_64-unknown-l4re-uclibc` | ? |  |
 [`x86_64-unknown-linux-none`](platform-support/x86_64-unknown-linux-none.md) | * |  | 64-bit Linux with no libc
+[`x86_64-unknown-managarm-mlibc`](platform-support/managarm.md) | ? |   | x86_64 Managarm
 [`x86_64-unknown-openbsd`](platform-support/openbsd.md) | ✓ | ✓ | 64-bit OpenBSD
 [`x86_64-unknown-trusty`](platform-support/trusty.md) | ✓ |  |
 `x86_64-uwp-windows-gnu` | ✓ |  |
diff --git a/src/doc/rustc/src/platform-support/aarch64_be-unknown-linux-musl.md b/src/doc/rustc/src/platform-support/aarch64_be-unknown-linux-musl.md
new file mode 100644
index 00000000000..3e816dc8bfb
--- /dev/null
+++ b/src/doc/rustc/src/platform-support/aarch64_be-unknown-linux-musl.md
@@ -0,0 +1,49 @@
+# aarch64_be-unknown-linux-musl
+
+**Tier: 3**
+
+ARM64 Linux (big-endian) with musl-libc.
+
+## Target maintainers
+
+[@neuschaefer](https://github.com/neuschaefer)
+[@Gelbpunkt](https://github.com/Gelbpunkt)
+
+## Requirements
+
+The target requires a `aarch64_be-*-linux-musl` toolchain, which likely has to
+be built from source because this is a rare combination.  [Buildroot] provides
+a way of doing so:
+
+- select _Target options_ → _Target Architecture_ → _AArch64 (big endian)_
+- select _Toolchain_ → _C library_ → _musl_
+- select _Toolchain_ → _Enable C++ support_
+
+Host tools are supported.
+
+[Buildroot]: https://buildroot.org/
+
+
+## Building the target
+
+The target can be enabled in bootstrap.toml:
+
+```toml
+[build]
+target = ["aarch64_be-unknown-linux-musl"]
+
+[target.aarch64_be-unknown-linux-musl]
+cc          = "/path/to/buildroot/host/bin/aarch64_be-buildroot-linux-musl-cc"
+cxx         = "/path/to/buildroot/host/bin/aarch64_be-buildroot-linux-musl-c++"
+linker      = "/path/to/buildroot/host/bin/aarch64_be-buildroot-linux-musl-cc"
+ar          = "/path/to/buildroot/host/bin/aarch64_be-buildroot-linux-musl-ar"
+ranlib      = "/path/to/buildroot/host/bin/aarch64_be-buildroot-linux-musl-ranlib"
+musl-root   = "/path/to/buildroot/staging"
+runner      = "qemu-aarch64_be -L /path/to/buildroot/target"
+crt-static  = "/path/to/buildroot/target"
+```
+
+
+## Testing
+
+Binaries can be run under `qemu-aarch64_be` or under a big-endian Linux kernel.
diff --git a/src/doc/rustc/src/platform-support/managarm.md b/src/doc/rustc/src/platform-support/managarm.md
new file mode 100644
index 00000000000..aa2d5a7ac23
--- /dev/null
+++ b/src/doc/rustc/src/platform-support/managarm.md
@@ -0,0 +1,53 @@
+# `*-unknown-managarm-mlibc`
+
+**Tier: 3**
+
+## Target Maintainers
+
+- [@no92](https://github.com/no92)
+- [@64](https://github.com/64)
+- [@Dennisbonke](https://github.com/Dennisbonke)
+
+## Requirements
+
+This target is cross-compiled. There is currently no support for `std` yet. It generates binaries in the ELF format. Currently, we support the `x86_64`, `aarch64` and `riscv64gc` architectures. The examples below `$ARCH` should be substituted for one of the supported architectures.
+
+## Building the target
+
+Managarm has upstream support in LLVM since the release of 21.1.0.
+
+Set up your `bootstrap.toml` like this:
+
+```toml
+change-id = 142379
+
+[llvm]
+targets = "X86;AArch64;RISCV"
+download-ci-llvm = false
+
+[build]
+target = ["$ARCH-unknown-managarm-mlibc", "x86_64-unknown-linux-gnu"]
+
+[target.x86_64-unknown-linux-gnu]
+llvm-config = "/path/to/your/llvm/bin/llvm-config"
+
+[target.$ARCH-unknown-managarm-mlibc]
+llvm-config = "/path/to/your/llvm/bin/llvm-config"
+```
+
+## Building Rust programs
+
+Build a `$ARCH-managarm-gcc` using our [gcc fork](https://github.com/managarm/gcc).
+
+```toml
+[build]
+rustc = "/path/to/the/rust-prefix/bin/rustc"
+target = "$ARCH-unknown-managarm-mlibc"
+
+[target.$ARCH-unknown-managarm-mlibc]
+linker = "/path/to/the/managarm-gcc/bin/$ARCH-managarm-gcc"
+```
+
+## Testing
+
+This target does not support running the Rust testsuite yet.
diff --git a/src/doc/rustc/src/platform-support/riscv64a23-unknown-linux-gnu.md b/src/doc/rustc/src/platform-support/riscv64a23-unknown-linux-gnu.md
new file mode 100644
index 00000000000..2cbaaa86654
--- /dev/null
+++ b/src/doc/rustc/src/platform-support/riscv64a23-unknown-linux-gnu.md
@@ -0,0 +1,41 @@
+# `riscv64a23-unknown-linux-gnu`
+
+**Tier: 3**
+
+RISC-V target using the ratified [RVA23 Profile](https://github.com/riscv/riscv-profiles/blob/main/src/rva23-profile.adoc).
+This target will enable all mandary features of rva23u64 by default.
+
+## Target maintainers
+
+[@ZhongyaoChen](https://github.com/ZhongyaoChen)
+[@CaiWeiran](https://github.com/CaiWeiran)
+
+## Requirements
+
+This target can be sucessfully build on the following platform: ubuntu 24.04 (Linux Kernel version 6.8.0, glibc 2.39).
+
+Other platforms may work, but are not tested. Please contanct if you encounter any issues.
+
+## Building the target
+
+Tier-3 target is not distributed through `rustup`.
+
+You need to build your own Rust, the target can be build with:
+
+```bash
+./x build --target riscv64a23-unknown-linux-gnu
+```
+
+## Building Rust programs
+
+Add the toolchain:
+
+```bash
+rustup toolchain link rva23-toolchain {path-to-rust}/build/host/stage2
+```
+
+Then cross compile crates with:
+
+```bash
+RUSTFLAGS="-C linker=riscv64-linux-gnu-gcc" cargo +rva23-toolchain build --target=riscv64a23-unknown-linux-gnu
+```
diff --git a/src/doc/rustc/src/platform-support/vxworks.md b/src/doc/rustc/src/platform-support/vxworks.md
index 3fccee80722..091c757a2ee 100644
--- a/src/doc/rustc/src/platform-support/vxworks.md
+++ b/src/doc/rustc/src/platform-support/vxworks.md
@@ -20,6 +20,7 @@ Target triplets available:
 ## Target maintainers
 
 [@biabbas](https://github.com/biabbas)
+[@hax0kartik](https://github.com/hax0kartik)
 
 ## Requirements
 
diff --git a/src/doc/rustc/src/platform-support/windows-msvc.md b/src/doc/rustc/src/platform-support/windows-msvc.md
index 71dc4ddc2e6..826c75b79c5 100644
--- a/src/doc/rustc/src/platform-support/windows-msvc.md
+++ b/src/doc/rustc/src/platform-support/windows-msvc.md
@@ -4,13 +4,10 @@ Windows MSVC targets.
 
 **Tier 1 with host tools:**
 
+- `aarch64-pc-windows-msvc`: Windows on ARM64.
 - `i686-pc-windows-msvc`: Windows on 32-bit x86.
 - `x86_64-pc-windows-msvc`: Windows on 64-bit x86.
 
-**Tier 2 with host tools:**
-
-- `aarch64-pc-windows-msvc`: Windows on ARM64.
-
 ## Target maintainers
 
 [@ChrisDenton](https://github.com/ChrisDenton)
diff --git a/src/doc/rustdoc/src/images/collapsed-long-item.png b/src/doc/rustdoc/src/images/collapsed-long-item.png
index c382870c64a..6de759fbeb9 100644
--- a/src/doc/rustdoc/src/images/collapsed-long-item.png
+++ b/src/doc/rustdoc/src/images/collapsed-long-item.png
Binary files differdiff --git a/src/doc/rustdoc/src/images/collapsed-trait-impls.png b/src/doc/rustdoc/src/images/collapsed-trait-impls.png
index f685656e09a..96cc7db6798 100644
--- a/src/doc/rustdoc/src/images/collapsed-trait-impls.png
+++ b/src/doc/rustdoc/src/images/collapsed-trait-impls.png
Binary files differdiff --git a/src/doc/rustdoc/src/unstable-features.md b/src/doc/rustdoc/src/unstable-features.md
index bb28e3abbf3..25c929a1dba 100644
--- a/src/doc/rustdoc/src/unstable-features.md
+++ b/src/doc/rustdoc/src/unstable-features.md
@@ -196,7 +196,7 @@ to enable.
 
 ### Document keywords
 
-This is for Rust compiler internal use only.
+This is for internal use in the std library.
 
 Rust keywords are documented in the standard library (look for `match` for example).
 
@@ -211,6 +211,23 @@ To do so, the `#[doc(keyword = "...")]` attribute is used. Example:
 mod empty_mod {}
 ```
 
+### Document builtin attributes
+
+This is for internal use in the std library.
+
+Rust builtin attributes are documented in the standard library (look for `repr` for example).
+
+To do so, the `#[doc(attribute = "...")]` attribute is used. Example:
+
+```rust
+#![feature(rustdoc_internals)]
+#![allow(internal_features)]
+
+/// Some documentation about the attribute.
+#[doc(attribute = "repr")]
+mod empty_mod {}
+```
+
 ### Use the Rust logo as the crate logo
 
 This is for official Rust project use only.
diff --git a/src/doc/style-guide/src/README.md b/src/doc/style-guide/src/README.md
index f42b9cb5978..c3788c97ae6 100644
--- a/src/doc/style-guide/src/README.md
+++ b/src/doc/style-guide/src/README.md
@@ -112,6 +112,14 @@ fn bar() {}
 fn baz() {}
 ```
 
+### Trailing whitespace
+
+Do not include trailing whitespace on the end of any line. This includes blank
+lines, comment lines, code lines, and string literals.
+
+Note that avoiding trailing whitespace in string literals requires care to
+preserve the value of the literal.
+
 ### Sorting
 
 In various cases, the default Rust style specifies to sort things. If not
@@ -225,8 +233,8 @@ newline after the opening sigil, and a newline before the closing sigil.
 
 Prefer to put a comment on its own line. Where a comment follows code, put a
 single space before it. Where a block comment appears inline, use surrounding
-whitespace as if it were an identifier or keyword. Do not include trailing
-whitespace after a comment or at the end of any line in a multi-line comment.
+whitespace as if it were an identifier or keyword.
+
 Examples:
 
 ```rust
diff --git a/src/doc/unstable-book/src/compiler-flags/sanitizer.md b/src/doc/unstable-book/src/compiler-flags/sanitizer.md
index 2f9d4d22e5a..493256de99d 100644
--- a/src/doc/unstable-book/src/compiler-flags/sanitizer.md
+++ b/src/doc/unstable-book/src/compiler-flags/sanitizer.md
@@ -244,18 +244,16 @@ See the [Clang ControlFlowIntegrity documentation][clang-cfi] for more details.
 
 ## Example 1: Redirecting control flow using an indirect branch/call to an invalid destination
 
-```rust,ignore (making doc tests pass cross-platform is hard)
-use std::arch::naked_asm;
-use std::mem;
-
+```rust
 fn add_one(x: i32) -> i32 {
     x + 1
 }
 
 #[unsafe(naked)]
-pub extern "C" fn add_two(x: i32) {
+# #[cfg(all(target_os = "linux", target_arch = "x86_64"))]
+pub extern "sysv64" fn add_two(x: i32) {
     // x + 2 preceded by a landing pad/nop block
-    naked_asm!(
+    std::arch::naked_asm!(
         "
          nop
          nop
@@ -281,16 +279,18 @@ fn main() {
 
     println!("The answer is: {}", answer);
 
-    println!("With CFI enabled, you should not see the next answer");
-    let f: fn(i32) -> i32 = unsafe {
-        // Offset 0 is a valid branch/call destination (i.e., the function entry
-        // point), but offsets 1-8 within the landing pad/nop block are invalid
-        // branch/call destinations (i.e., within the body of the function).
-        mem::transmute::<*const u8, fn(i32) -> i32>((add_two as *const u8).offset(5))
-    };
-    let next_answer = do_twice(f, 5);
-
-    println!("The next answer is: {}", next_answer);
+#   #[cfg(all(target_os = "linux", target_arch = "x86_64"))] {
+        println!("With CFI enabled, you should not see the next answer");
+        let f: fn(i32) -> i32 = unsafe {
+            // Offset 0 is a valid branch/call destination (i.e., the function entry
+            // point), but offsets 1-8 within the landing pad/nop block are invalid
+            // branch/call destinations (i.e., within the body of the function).
+            std::mem::transmute::<*const u8, fn(i32) -> i32>((add_two as *const u8).offset(5))
+        };
+        let next_answer = do_twice(f, 5);
+
+        println!("The next answer is: {}", next_answer);
+#   }
 }
 ```
 Fig. 1. Redirecting control flow using an indirect branch/call to an invalid
diff --git a/src/doc/unstable-book/src/language-features/extended-varargs-abi-support.md b/src/doc/unstable-book/src/language-features/extended-varargs-abi-support.md
deleted file mode 100644
index b20c30ec8f1..00000000000
--- a/src/doc/unstable-book/src/language-features/extended-varargs-abi-support.md
+++ /dev/null
@@ -1,10 +0,0 @@
-# `extended_varargs_abi_support`
-
-The tracking issue for this feature is: [#100189]
-
-[#100189]: https://github.com/rust-lang/rust/issues/100189
-
-------------------------
-
-This feature adds the possibility of using `sysv64`, `win64` or `efiapi` calling
-conventions on functions with varargs.