[llvm] [flang-rt] replace the triple dir to 'aix' for flang-rt to be consistent with clang on AIX. (PR #130875)

[Daniel Chen via llvm-commits]

DanielCChen wrote:

> The snippet was copied from
> 
> https://github.com/llvm/llvm-project/blob/665299eb3e7a142199e2c22eb294c5e01ef1655d/compiler-rt/cmake/Modules/CompilerRTUtils.cmake#L463-L508
> 
> Do you intend to update it there as well? Or maybe I missed that compiler-rt is lower-casing the triple somewhere before calling get_compiler_rt_target?

Actually, `compiler-rt` build on AIX doesn't call `get_compiler_rt_target`, so it shouldn't be affected.

https://github.com/llvm/llvm-project/pull/130875