[llvm] [GlobalISel][AArch64][AMDGPU] Expand FPOWI into series of multiplication (PR #95217)

[David Green via llvm-commits]

https://github.com/davemgreen commented:

Should this call isBeneficialToExpandPowI too? Otherwise it might expand to a lot of multiplies.

https://github.com/llvm/llvm-project/pull/95217