new interface error messages

new interface error messages

	package main
	func main() {
		var i interface { } = 1;
		a := i.(*[]byte);
	}

interface { } is int, not *[]uint8
throw: interface conversion

	package main
	func main() {
		var i interface { };
		a := i.(*[]byte);
	}

interface is nil, not *[]uint8
throw: interface conversion

	package main
	func main() {
		i := sys.unreflect(0, "*bogus");
		a := i.(*[]byte);
	}

interface { } is *bogus, not *[]uint8
throw: interface conversion

R=r
DELTA=30  (24 added, 2 deleted, 4 changed)
OCL=18548
CL=18565