Fix codegen for null different sized pointer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194932 91177308-0d34-0410-b5e6-96231b3b80d8
Fix assert on unaligned access to global with different address space size.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194934 91177308-0d34-0410-b5e6-96231b3b80d8