Merge ref '32e7a4b92b10' from rust-lang/rust

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

Upstream ref: 32e7a4b92b109c24e9822c862a7c74436b50e564
Filtered ref: d39f3479bfafb04026ed3afec68aa671d13e9c3c

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

2 files changed, 17 insertions, 2 deletions

diff --git a/src/doc/rustc-dev-guide/src/tests/directives.md b/src/doc/rustc-dev-guide/src/tests/directives.md
index 5c3ae359ba0..89e4d3e9b58 100644
--- a/src/doc/rustc-dev-guide/src/tests/directives.md
+++ b/src/doc/rustc-dev-guide/src/tests/directives.md
@@ -293,8 +293,6 @@ See [Pretty-printer](compiletest.md#pretty-printer-tests).
 
 - `no-auto-check-cfg` — disable auto check-cfg (only for `--check-cfg` tests)
 - [`revisions`](compiletest.md#revisions) — compile multiple times
-- [`unused-revision-names`](compiletest.md#ignoring-unused-revision-names) -
-      suppress tidy checks for mentioning unknown revision names
 -[`forbid-output`](compiletest.md#incremental-tests) — incremental cfail rejects
       output pattern
 - [`should-ice`](compiletest.md#incremental-tests) — incremental cfail should
@@ -315,6 +313,17 @@ test suites that use those tools:
 - `llvm-cov-flags` adds extra flags when running LLVM's `llvm-cov` tool.
   - Used by [coverage tests](compiletest.md#coverage-tests) in `coverage-run` mode.
 
+### Tidy specific directives
+
+The following directives control how the [tidy script](../conventions.md#formatting)
+verifies tests.
+
+- `ignore-tidy-target-specific-tests` disables checking that the appropriate
+  LLVM component is required (via a `needs-llvm-components` directive) when a
+  test is compiled for a specific target (via the `--target` flag in a
+  `compile-flag` directive).
+- [`unused-revision-names`](compiletest.md#ignoring-unused-revision-names) -
+      suppress tidy checks for mentioning unknown revision names.
 
 ## Substitutions
 
diff --git a/src/doc/rustdoc/src/unstable-features.md b/src/doc/rustdoc/src/unstable-features.md
index 27910ad0ab7..7bd2970eee7 100644
--- a/src/doc/rustdoc/src/unstable-features.md
+++ b/src/doc/rustdoc/src/unstable-features.md
@@ -395,6 +395,12 @@ flags to control that behavior. When the `--extern-html-root-url` flag is given
 one of your dependencies, rustdoc use that URL for those docs. Keep in mind that if those docs exist
 in the output directory, those local docs will still override this flag.
 
+The names in this flag are first matched against the names given in the `--extern name=` flags,
+which allows selecting between multiple crates with the same name (e.g. multiple versions of
+the same crate). For transitive dependencies that haven't been loaded via an `--extern` flag, matching
+falls backs to using crate names only, without ability to distinguish between multiple crates with
+the same name.
+
 ## `-Z force-unstable-if-unmarked`
 
 Using this flag looks like this: