[DAGCombiner] split i1 select-of-constants from non-i1 case; NFCI

I can't find any tests of the non-i1 code path, so it may be unnecessary at this point.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@295463 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed