[InstCombine] adjust shuffle undef propagation tests; NFC

These are the updated baseline tests for D52548 -
I'm putting the tests next to the tests where the transform 
functions as expected, so we can see the intended/unintended
consequences.

Patch by: @sheredom (Neil Henning)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@343328 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed