revert r314984: revert r314698 - [InstCombine] remove one-use restriction for icmp (shr exact X, C1), C2 --> icmp X, (C2<<C1)

Recommitting r314698. The bug exposed by this change should be fixed with:
https://reviews.llvm.org/rL315579 



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315857 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed