[llvm] [FPEnv][PowerPC] Correct one more strictfp test. (PR #94793)

[Chen Zheng via llvm-commits]

chenzheng1030 wrote:

> If setflm readflm have IntrStrictFP added in their tablegen files then this Verifier change will always reject any use of them outside of a strictfp function.

If so, I don't think we need to add `IntrStrictFP` for these two builtins? These two builtins are needed in non-constraint environment to change the rounding mode, floating point exception behavior.

https://github.com/llvm/llvm-project/pull/94793