isKnownNonNull needs to consider globals in non-zero address spaces.

Globals in address spaces other than one may have 0 as a valid address,
so we should not assume that they can be null.

Reviewed by Philip Reames.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246137 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed