Teach InstructionSimplify about pointer address spaces

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187635 91177308-0d34-0410-b5e6-96231b3b80d8
Temporarily revert "Debug Info Finder|Verifier: handle DbgLoc attached to
instructions." in an attempt to bring back some bots.

This reverts commit r187609.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187638 91177308-0d34-0410-b5e6-96231b3b80d8