[HardwareLoops] Add support for strictfp functions. (#84531)

This pass was adding new function calls without adding the strictfp
attribute as required by the rules laid out in the langref. With this
change a make check has 4-5 fewer failing tests with the Verifier
changes in D146845.

LangRef:
https://llvm.org/docs/LangRef.html#constrained-floating-point-intrinsics

Test failures found with "https://reviews.llvm.org/D146845".