For PR1187:

Some changes to get the smbd.ll test case working:
1. Move the logic for CSRETCC->sret attribute out of the ResolveDefinitions
   code and into getExistingValue. This resolves it much earlier and works
   in function scope as well.
2. Fix handling of CSRETCC->sret for the store instruction.
3. Rewrite the code for handling renaming to factor in linkage types.
4. Rename a structure filed for a PATypeInfo* so it doesn't get confused
   with a field for a Type*.

llvm-svn: 34043