[llvm] [PowerPC] Remove `UnsafeFPMath` uses (PR #154901)

[Amy Kwan via llvm-commits]

================
@@ -8925,9 +8919,8 @@ SDValue PPCTargetLowering::LowerINT_TO_FP(SDValue Op,
     //
     // However, if -enable-unsafe-fp-math is in effect, accept double
----------------
amy-kwan wrote:

Nit: It would be good to update this comment if we are removing the check for the option.

https://github.com/llvm/llvm-project/pull/154901