[InstCombine] Add test cases to demonstrate instcombine increasing instruction...

[InstCombine] Add test cases to demonstrate instcombine increasing instruction count when trying to fold (select (icmp eq (and X, C1), 0), Y, (or Y, C2))->(or (shl (and X, C1), C3), y) when the pieces have multiple uses.

llvm-svn: 305509