Audit debug test runners to drop `--test-args clang` filters on run-make tests

[jieyouxu]

Context

Only two CI jobs have RUSTBUILD_FORCE_CLANG_BASED_TESTS 1 set, which is a necessary condition for //@ needs-force-clang-based-tests run-make tests to run. These tests (at the time when this issue was opened) pass a --test-args clang filter to the run-make test suite, meaning only run-make tests with clang in their name will run. This is a footgun which meant that several //@ needs-force-clang-based-tests run-make tests never ran in any CI jobs.

Known test runners:

• x86_64-gnu-debug
  • Addressed by Run the full stage 2 run-make test suite in x86_64-gnu-debug #131917
• aarch64-gnu-debug
  • Addressed by Liberate aarch64-gnu-debug from the shackles of --test-args=clang #132646

[jieyouxu]

I don't think there's anymore --test-args clang left, closing as resolved.