[InstCombine] move foldICmpDivConstConst() contents to foldICmpDivConstant(); NFCI

There was no logic in foldICmpDivConstant, so no need for a separate function.
The code is directly copy/pasted, so further cleanups to follow.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279685 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed