8034223: Most-specific should not have any special treatment for boxed vs. unboxed types

Rewrite most-specific logic to conform to JLS 8 15.12.2.5

Reviewed-by: vromero

langtools/test/tools/javac/lambda/MostSpecific12.java

@@ -0,0 +1,38 @@
+/*
+ * @test /nodynamiccopyright/
+ * @bug 8034223
+ * @summary Most-specific testing with inference variables in function parameter types
+ * @compile/fail/ref=MostSpecific12.out -XDrawDiagnostics MostSpecific12.java
+ */
+class MostSpecific12 {
+
+    interface I<T> { void take(T arg1, String arg2); }
+    interface J<T> { void take(String arg1, T arg2); }
+    interface K { void take(String arg1, String arg2); }
+
+    <T> void m1(I<T> arg) {}
+    void m1(K arg) {}
+
+    <T> void m2(J<T> arg) {}
+    <T> void m2(K arg) {}
+
+    <T> void m3(I<T> arg) {}
+    <T> void m3(J<T> arg) {}
+
+    void test() {
+        m1((String s1, String s2) -> {}); // ok
+        m2((String s1, String s2) -> {}); // ok
+        m3((String s1, String s2) -> {}); // error
+
+        m1(this::referencedMethod); // ok
+        m2(this::referencedMethod); // ok
+        m3(this::referencedMethod); // error
+
+        m1(String::compareTo); // ok
+        m2(String::compareTo); // ok
+        m3(String::compareTo); // error
+    }
+
+    void referencedMethod(String s1, String s2) {}
+
+}