This covers the patterns we use for widening 128/256 comparisons to 512-bit when
AVX512VL isn't supported.
[Constants] Simplify type checking switch in ConstantExpr::get.
Remove duplicate checks that both operands have the same type. This is checked
before the switch.
Use 'integer' or 'floating-point' instead of 'arithmetic' type. I think this
might be a leftover to the days when floating point and integer operations
shared the same opcodes.