Don't mutate the traits on builtin types.
Don't mutate the traits on builtin types.

	mktylike() should return a generic type based on the builtin,
	and that means that if we mutate the builtin, we will be adding
	traits to our literals.

	This is wrong on multiple levels. First off, it means that
	'@t :: numeric,integral @t' will now require whatever other
	types are implemented over literals. And second, it means that
	if, for example, a trait is implemented for flt64, flt32
	literals will also need it.

oridb/mc,oridb/mc,oridb/mc,oridb/mc