ci: run the full run-make test suite

Instead of filtering `run-make` tests whose test names contain the
`clang` substring.

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

@@ -49,9 +49,7 @@ ENV RUST_CONFIGURE_ARGS \
 #   (without necessarily testing the result).
 # - 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.
 
 ENV SCRIPT \
   python3 ../x.py --stage 2 build && \
-  python3 ../x.py --stage 2 test tests/run-make --test-args clang
+  python3 ../x.py --stage 2 test tests/run-make