[InstCombine] Remove insertRangeTest code that handles the equality case.

For equality, the function called getTrue/getFalse with the VT
of the comparison input. But getTrue/getFalse need the boolean VT.
So if this code ever executed, it would assert.

I believe these cases are removed by InstSimplify so we don't get here.

So this patch just fixes up an assert to exclude the equality
possibility and removes the broken code.

llvm-svn: 366649