Add address space argument to allowsUnalignedMemoryAccess.

On R600, some address spaces have more strict alignment
requirements than others.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200887 91177308-0d34-0410-b5e6-96231b3b80d8
Pass address space to allowsUnalignedMemoryAccesses

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200888 91177308-0d34-0410-b5e6-96231b3b80d8