[X86] Remove some InstRWs for plain store instructions on Sandy Bridge.

We were forcing the latency of these instructions to 5 cycles, but every other scheduler model had them as 1 cycle. I'm sure I didn't get everything, but this gets a big portion.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@329252 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed