Summary
-------

The javac compiler should not accept private method references with a type variable receiver.

Problem
-------

JLS 4.4 specifies that:

    The members of a type variable X with bound T & I 1 & ... & I n are the members of
    the intersection type (§4.9) T & I 1 & ... & I n appearing at the point where the type
    variable is declared.

So code like:

    import java.util.function.*;
    class Test {
        private String asString() {
            return "bar";
        }

        static <T extends Test> Function<T, String> foo() {
            return T::asString;
        }
    }

should be rejected by javac as private method `asString` is not a member of type variable `T` 

Solution
--------

The proposed solution is to sync javac with the specification so that private method references with type variable receiver are rejected by javac

Specification
-------------

No specification changes are required.