Change the x86 32-bit scheduler to register pressure and fix up the

Change the x86 32-bit scheduler to register pressure and fix up the
corresponding testcases back to the previous versions.

Fixes some performance regressions only seen on 32-bit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127441 91177308-0d34-0410-b5e6-96231b3b80d8