Fixes #4188 .

This PR improves the resolution of a reference expression of the form Primary, followed by :: and a method name.".

JLS §15.13.1: "If the method reference expression has the form Primary :: [TypeArguments] Identifier"

This is FORM 2: The scope is an expression (e.g., foo, myString, System.out)

CRITICAL: In this form, the expression is evaluated and becomes the BOUND RECEIVER at method reference creation time, not at invocation time.

The potentially applicable methods are the member methods of the type of the Primary that are not static

For bound instance methods: ALL functional interface parameters map to method parameters
The receiver is NOT part of paramTypes - it's already bound to the expression result

Example from failing test:

Foo foo = new Foo();
Optional<Integer> priority = Optional.of(4);
priority.map(foo::convert).orElse("0");

Analysis:

• scope = foo (a Primary expression, not a type)
• foo is evaluated → becomes bound receiver
• map() expects Function<Integer, String>
• paramTypes = [Integer] (from Function's parameter type)
• convert(int) signature: takes 1 parameter
• ALL paramTypes [Integer] go to method parameters
• Match: convert(int) with [Integer] ✓