TableGen fix for the new machine model.

Properly handle cases where a group of instructions have different
SchedRW lists with the same itinerary class.
This was supposed to work, but I left in an early break.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177317 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed