Once again, because i am poking around with go/types internals, i have spotted a bug in the type-checker.

The code below type-checks without any error:

package test

func test() {
outer:
	for range "aa" {
		break outer
	}

	for range "aa" {
		break outer
	}
}

This happens because lstmt:

is assigned and never cleared, thus:

is executed with a wrong label (for the second for statement).

CC @adonovan @griesemer