[SimplifyLibCalls] pow(x, -0.5) -> 1.0 / sqrt(x).

Differential Revision:  https://reviews.llvm.org/D28479

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291486 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed