[X86] Fix bad regular expressions in the scheduler models. Question marks should...

[X86] Fix bad regular expressions in the scheduler models. Question marks should be outside of multicharacter parenthesized expressions

If the question mark is inside the parentheses it only applies to the single character proceeding it.

I had to make a few additional cleanups to fix some duplicate warnings that were exposed by fixing this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320279 91177308-0d34-0410-b5e6-96231b3b80d8