[InstCombine] combine foldAndOfFCmps and foldOrOfFcmps; NFCI

In addition to removing chunks of duplicated code, we don't
want these to diverge. If there's a fold for one, there
should be a fold of the other via DeMorgan's Laws.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312420 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed