Rename needs-matching-clang to needs-force-clang-based-tests

This header is much more restrictive than its old name would suggest. As a
result, most of the tests that use it don't actually run in any CI jobs.

Author: Zalathar

src/ci/docker/host-x86_64/x86_64-gnu-debug/Dockerfile

@@ -47,7 +47,7 @@ ENV RUST_CONFIGURE_ARGS \
 # This job appears to be checking two separate things:
 # - That we can build the compiler with `--enable-debug`
 #   (without necessarily testing the result).
-# - That the tests with `//@ needs-matching-clang` pass, since they
+# - That the tests with `//@ needs-force-clang-based-tests` pass, since they
 #   don't run by default unless RUSTBUILD_FORCE_CLANG_BASED_TESTS is set.
 #   - FIXME(https://github.com/rust-lang/rust/pull/126155#issuecomment-2156314273):
 #     Currently we only run the subset of tests with "clang" in their name.

src/tools/compiletest/src/header.rs

@@ -854,9 +854,9 @@ const KNOWN_DIRECTIVE_NAMES: &[&str] = &[
     "needs-asm-support",
     "needs-dlltool",
     "needs-dynamic-linking",
+    "needs-force-clang-based-tests",
     "needs-git-hash",
     "needs-llvm-components",
-    "needs-matching-clang",
     "needs-profiler-support",
     "needs-relocation-model-pic",
     "needs-run-enabled",

src/tools/compiletest/src/header/needs.rs

@@ -100,9 +100,9 @@ pub(super) fn handle_needs(
             ignore_reason: "ignored when profiler support is disabled",
         },
         Need {
-            name: "needs-matching-clang",
+            name: "needs-force-clang-based-tests",
             condition: config.run_clang_based_tests_with.is_some(),
-            ignore_reason: "ignored when the used clang does not match the built LLVM",
+            ignore_reason: "ignored when RUSTBUILD_FORCE_CLANG_BASED_TESTS is not set",
         },
         Need {
             name: "needs-xray",

tests/run-make/cross-lang-lto-clang/Makefile

@@ -1,4 +1,4 @@
-# needs-matching-clang
+# needs-force-clang-based-tests
 
 # This test makes sure that cross-language inlining actually works by checking
 # the generated machine code.

tests/run-make/cross-lang-lto-pgo-smoketest/Makefile

@@ -1,4 +1,7 @@
-# needs-matching-clang
+# needs-force-clang-based-tests
+
+# FIXME(#126180): This test doesn't actually run anywhere, because the only
+# CI job that sets RUSTBUILD_FORCE_CLANG_BASED_TESTS runs very few tests.
 
 # This test makes sure that cross-language inlining can be used in conjunction
 # with profile-guided optimization. The test only tests that the whole workflow

tests/run-make/cross-lang-lto-riscv-abi/rmake.rs

@@ -1,8 +1,11 @@
 //! Make sure that cross-language LTO works on riscv targets,
 //! which requires extra `target-abi` metadata to be emitted.
-//@ needs-matching-clang
+//@ needs-force-clang-based-tests
 //@ needs-llvm-components riscv
 
+// FIXME(#126180): This test doesn't actually run anywhere, because the only
+// CI job that sets RUSTBUILD_FORCE_CLANG_BASED_TESTS runs very few tests.
+
 use run_make_support::{bin_name, clang, llvm_readobj, rustc};
 use std::{
     env,

tests/run-make/issue-84395-lto-embed-bitcode/Makefile

@@ -1,4 +1,7 @@
-# needs-matching-clang
+# needs-force-clang-based-tests
+
+# FIXME(#126180): This test doesn't actually run anywhere, because the only
+# CI job that sets RUSTBUILD_FORCE_CLANG_BASED_TESTS runs very few tests.
 
 # This test makes sure the embed bitcode in elf created with
 # lto-embed-bitcode=optimized is valid llvm BC module.

tests/run-make/wasm-override-linker/Makefile

@@ -1,4 +1,7 @@
-# needs-matching-clang
+# needs-force-clang-based-tests
+
+# FIXME(#126180): This test doesn't actually run anywhere, because the only
+# CI job that sets RUSTBUILD_FORCE_CLANG_BASED_TESTS runs very few tests.
 
 include ../tools.mk