Auto merge of #78319 - jonas-schievink:rollup-vzj8a6l, r=jonas-schievink

Rollup of 15 pull requests

Successful merges:

 - #76649 (Add a spin loop hint for Arc::downgrade)
 - #77392 (add `insert` to `Option`)
 - #77716 (Revert "Allow dynamic linking for iOS/tvOS targets.")
 - #78109 (Check for exhaustion in RangeInclusive::contains and slicing)
 - #78198 (Simplify assert terminator only if condition evaluates to expected value)
 - #78243 (--test-args flag description)
 - #78249 (improve const infer error)
 - #78250 (Document inline-const)
 - #78264 (Add regression test for issue-77475)
 - #78274 (Update description of Empty Enum for accuracy)
 - #78278 (move `visit_predicate` into `TypeVisitor`)
 - #78292 (Loop instead of recursion)
 - #78293 (Always store Rustdoc theme when it's changed)
 - #78300 (Make codegen coverage_context optional, and check)
 - #78307 (Revert "Set .llvmbc and .llvmcmd sections as allocatable")

Failed merges:

r? `@ghost`

5 files changed, 69 insertions, 7 deletions

diff --git a/src/bootstrap/flags.rs b/src/bootstrap/flags.rs
index 22cfd0c5643..3834e50e3fa 100644
--- a/src/bootstrap/flags.rs
+++ b/src/bootstrap/flags.rs
@@ -232,7 +232,13 @@ To learn more about a subcommand, run `./x.py <subcommand> -h`",
         match subcommand.as_str() {
             "test" | "t" => {
                 opts.optflag("", "no-fail-fast", "Run all tests regardless of failure");
-                opts.optmulti("", "test-args", "extra arguments", "ARGS");
+                opts.optmulti(
+                    "",
+                    "test-args",
+                    "extra arguments to be passed for the test tool being used \
+                        (e.g. libtest, compiletest or rustdoc)",
+                    "ARGS",
+                );
                 opts.optmulti(
                     "",
                     "rustc-args",
diff --git a/src/doc/unstable-book/src/language-features/inline-const.md b/src/doc/unstable-book/src/language-features/inline-const.md
new file mode 100644
index 00000000000..00e1c79ca3f
--- /dev/null
+++ b/src/doc/unstable-book/src/language-features/inline-const.md
@@ -0,0 +1,45 @@
+# `inline_const`
+
+The tracking issue for this feature is: [#76001]
+
+------
+
+This feature allows you to use inline constant expressions. For example, you can
+turn this code:
+
+```rust
+# fn add_one(x: i32) -> i32 { x + 1 }
+const MY_COMPUTATION: i32 = 1 + 2 * 3 / 4;
+
+fn main() {
+    let x = add_one(MY_COMPUTATION);
+}
+```
+
+into this code:
+
+```rust
+#![feature(inline_const)]
+
+# fn add_one(x: i32) -> i32 { x + 1 }
+fn main() {
+    let x = add_one(const { 1 + 2 * 3 / 4 });
+}
+```
+
+You can also use inline constant expressions in patterns:
+
+```rust
+#![feature(inline_const)]
+
+const fn one() -> i32 { 1 }
+
+let some_int = 3;
+match some_int {
+    const { 1 + 2 } => println!("Matched 1 + 2"),
+    const { one() } => println!("Matched const fn returning 1"),
+    _ => println!("Didn't match anything :("),
+}
+```
+
+[#76001]: https://github.com/rust-lang/rust/issues/76001
diff --git a/src/librustdoc/html/static/storage.js b/src/librustdoc/html/static/storage.js
index a027d6845ea..ef734f260af 100644
--- a/src/librustdoc/html/static/storage.js
+++ b/src/librustdoc/html/static/storage.js
@@ -94,6 +94,12 @@ function switchTheme(styleElem, mainStyleElem, newTheme, saveTheme) {
     var fullNewTheme = newTheme + resourcesSuffix + ".css";
     var newHref = mainStyleElem.href.replace(fullBasicCss, fullNewTheme);
 
+    // If this new value comes from a system setting or from the previously
+    // saved theme, no need to save it.
+    if (saveTheme === true) {
+        updateLocalStorage("rustdoc-theme", newTheme);
+    }
+
     if (styleElem.href === newHref) {
         return;
     }
@@ -112,11 +118,6 @@ function switchTheme(styleElem, mainStyleElem, newTheme, saveTheme) {
     });
     if (found === true) {
         styleElem.href = newHref;
-        // If this new value comes from a system setting or from the previously
-        // saved theme, no need to save it.
-        if (saveTheme === true) {
-            updateLocalStorage("rustdoc-theme", newTheme);
-        }
     }
 }
 
diff --git a/src/test/ui/const-generics/infer/issue-77092.stderr b/src/test/ui/const-generics/infer/issue-77092.stderr
index e84ff8baeea..63facbf3b8c 100644
--- a/src/test/ui/const-generics/infer/issue-77092.stderr
+++ b/src/test/ui/const-generics/infer/issue-77092.stderr
@@ -2,7 +2,7 @@ error[E0282]: type annotations needed
   --> $DIR/issue-77092.rs:13:26
    |
 LL |         println!("{:?}", take_array_from_mut(&mut arr, i));
-   |                          ^^^^^^^^^^^^^^^^^^^ cannot infer the value of the constant `{_: usize}`
+   |                          ^^^^^^^^^^^^^^^^^^^ cannot infer the value of const parameter `N` declared on the function `take_array_from_mut`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/macros/issue-77475.rs b/src/test/ui/macros/issue-77475.rs
new file mode 100644
index 00000000000..7b32a33ea4f
--- /dev/null
+++ b/src/test/ui/macros/issue-77475.rs
@@ -0,0 +1,10 @@
+// check-pass
+// Regression test of #77475, this used to be ICE.
+
+#![feature(decl_macro)]
+
+use crate as _;
+
+pub macro ice(){}
+
+fn main() {}