[llvm] [PowerPC] Fix IS_FPCLASS crash on 32-bit AIX targets for fcFinite/fcInf/fcInf|fcNan masks (PR #213298)

[Daniel Chen via llvm-commits]

DanielCChen wrote:

Note: This is Bob's suggestion of change and reasoning based on the two principle requirments:
1. The change should preserve the intent of PR https://github.com/llvm/llvm-project/pull/212565.
2. The change indeed fixes the build failure in `compiler-rt/builtins` as well as other masks that potentially are at risk.

Could reviewers please check that?


https://github.com/llvm/llvm-project/pull/213298