Annotate X86InstrCompiler.td with SchedRW lists.

Add a new WriteZero SchedWrite type for the common dependency-breaking
instructions that clear a register.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177442 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed