[X86] Change IMUL with immediate instruction order to ri8 instructions come before ri/ri32 instructions.

This will ensure IMUL64ri8 is tried before IMUL64ri32. For IMUL32 and IMUL16 the
order doesn't really matter because only the ri8 versions use a predicate. That
automatically gives them priority.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358360 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed