[X86] Scrub scheduling information for MUL/IMUL on Intel CPUs.

This removes a bunch of unnecessary InstRW overrides. It also cleans up the missing information from the Sandy Bridge model. Other fixes to other models.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@330308 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed