Revert r310869 "[InstSimplify][InstCombine] Modify the interface of decomposeBitTestICmp and use it in the InstSimplify"

Failed to add the two files that moved. And then added an extra change I didn't mean to while trying to fix that. Reverting everything.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@310873 91177308-0d34-0410-b5e6-96231b3b80d8
7 files changed