[clang] [LoongArch][clang] Add support for option `-msimd=` and macro `__loongarch_simd_width`. (PR #97984)

[Zhaoxin Yang via cfe-commits]

ylzsx wrote:

> Hi, this test is failing on the AIX bot https://lab.llvm.org/buildbot/#/builders/64/builds/250/steps/6/logs/FAIL__Clang__loongarch-msimd_c
> 
> The reason is that -o is not a supported option with grep on AIX. Would you be able to adapt the test to avoid piping and use input redirection (so that the builtin grep is used, for example here: https://github.com/llvm/llvm-project/pull/83184/files. I'm not sure if this works with grep though) or use another command like sed?

@jakeegan Already fixed, see https://github.com/llvm/llvm-project/pull/98442.

https://github.com/llvm/llvm-project/pull/97984