Improve code generated for inputs like the following:

Improve code generated for inputs like the following:

    (if (if (and (object-type? (ucode-type fixnum) r)
		 (object-type? (ucode-type fixnum) l))
	    (fix:> r l)
	    (> r l))
	...)

Previously, the code generated for the call to `fix:>' was deficient
in that it pushed a continuation, performed the inline coded
comparison, then did a pop-return.  In fact, since the continuation is
known at that point, and is not being passed anywhere, there's no
reason to push anything on the stack.  These changes implement this.