[compiler-rt] [SPARC][builtins] Add sparcv9 arch name for 32-bit SPARC (PR #170133)

[via llvm-commits]

koachan wrote:

There's also another failure reported there: the [frexpl_interceptor.cpp failure](https://lab.llvm.org/buildbot/#/builders/13/builds/10850) which seem to happen because the sanitizer parts are built with system LLVM, which still doesn't have the `long double` fixes, while the sources being pulled already enables all the `long double` tests.

Any idea what should I do for it?

https://github.com/llvm/llvm-project/pull/170133