R600/SI: Fix crash in SIInstrInfo::areLoadsFromSameBasePtr()

This function assumed that SMRD instructions always have immediate
offsets, which is not always the case.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232957 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed