Elements.overrides does not check overrider membership

Elements.overrides does not check that the overrider method is a member of the class or interface from where that method presumably overrides the overridee.

Although the intent is clear, the spec does not say what happens when a non-member is passed:

    @param type the class or interface of which the first method is a member

An exception, the `false` result, or a note in the specification would seem to be in order. Consider this surprising result. Suppose:

    public class S { public void m() { } }
    public class T1 extends S { public void m() { } }
    public class T2 extends S { public void m() { } }

Then (pseudocode):

    Elements.overrides(/* overrider */ T2::m, /* overridee */ S::m, /* from */ T3) == true