8016175: Add bottom-up type-checking support for unambiguous method references

Type-checking of non-overloaded method references should be independent from target-type

Reviewed-by: jjg, vromero

langtools/test/tools/javac/lambda/MethodReference71.java

@@ -0,0 +1,26 @@
+/*
+ * @test /nodynamiccopyright/
+ * @bug 8016175
+ * @summary Add bottom-up type-checking support for unambiguous method references
+ * @compile/fail/ref=MethodReference71.out -XDrawDiagnostics MethodReference71.java
+ */
+class MethodReference71 {
+    interface F<X> {
+        void m(X x);
+    }
+
+    interface G<X> {
+        Integer m(X x);
+    }
+
+    void m1(Integer i) { }
+    void m2(Integer... i) { }
+
+    <Z> void g(F<Z> f) { }
+    <Z> void g(G<Z> g) { }
+
+    void test() {
+         g(this::m1); //ok
+         g(this::m2); //ambiguous (stuck!)
+    }
+}