Fix PR2590 by making PatternSortingPredicate actually be

Fix PR2590 by making PatternSortingPredicate actually be
ordered correctly.  Previously it would get in trouble when
two patterns were too similar and give them nondet ordering.
We force this by using the record ID order as a fallback.

The testsuite diff is due to alpha patterns being ordered
slightly differently, the change is a semantic noop afaict:

< 	lda $0,-100($16)
---
> 	subq $16,100,$0

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97509 91177308-0d34-0410-b5e6-96231b3b80d8