[compiler-rt] [compiler-rt] Disable tests for unavailable builtins (PR #158664)

[Martin Storsjö via llvm-commits]

mstorsjo wrote:

FYI, for visibility here as well - as https://github.com/llvm/llvm-project/pull/160687 actually made these changes work as intended, it showed up as failed tests on x86_64, in https://lab.llvm.org/buildbot/#/builders/66/builds/19787 - so I reverted them both in https://github.com/llvm/llvm-project/commit/f7e8350f0bcbe46a046cbedfef1e6e56928ea87b.

https://github.com/llvm/llvm-project/pull/158664