Add missing mayLoad flag to LHAUX8 and LWAUX.

All pre-increment load patterns need to set the mayLoad flag (since
they don't provide a DAG pattern).

This was missing for LHAUX8 and LWAUX, which is added by this patch.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177431 91177308-0d34-0410-b5e6-96231b3b80d8