[InstCombine] adjust shuffle tests with IR flags; NFC

Due to current limitations in constant analysis, we need flags
on add or mul to show propagation for the potential transform
suggested in these tests (no other binops currently report 
identity constants).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336101 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed