Fix broken optimization disabled by a logic bug.

Analyze GEPs. If the indices are all zero, transfer whether the pointer is
known to be not null through the GEP.

Add a few more cases for xor and shift instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35257 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed