[InstCombine][NFC] Add tests for one more masked merge pattern.

This pattern came up in D46494.
I'm pretty sure we want to canonicalize it from
	(x | ~m) & (y &  m)
to
	(x &  m) | (y & ~m)

https://rise4fun.com/Alive/TEM

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@331625 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed