SI-8219 Pending test to show suspicous overload in == in AnyRef

    % scalac-hash v2.11.0-M7 test/pending/neg/t8219-any-any-ref-equals.scala
    test/pending/neg/t8219-any-any-ref-equals.scala:5: error: overloaded method value == with alternatives:
      (x$1: AnyRef)Boolean <and>
      (x$1: Any)Boolean
     does not take type parameters
      "".==[Int]
         ^
    one error found

Usually for Java-originated methods, we are allow Object and Any
to unify pre-erasure in method signatures. This is handled in
`matchesParams`, and is predicated on whether the method type is
an instance of `JavaMethodType`

For instance, we are allowed to:

    scala> class C { override def equals(a: Any) = false }
    defined class C

On account of:

    scala> typeOf[Object].decl(nme.equals_).info.getClass
    res7: Class[_ <: $r.intp.global.Type] = class scala.reflect.internal.Types$JavaMethodType

But:

    scala> typeOf[Object].decl(nme.EQ).defString
    res8: String = final def ==(x$1: AnyRef): Boolean

    scala> typeOf[Object].decl(nme.EQ).info.getClass
    res9: Class[_ <: $r.intp.global.Type] = class scala.reflect.internal.Types$MethodType

More special casing is probably needed.

Author: retronym

test/pending/neg/t8219-any-any-ref-equals.scala

@@ -0,0 +1,6 @@
+object Test {
+  // The error message tells us that AnyRef#== and Any#== are overloaded.
+  // A real class couldn't define such an overload, why do we allow AnyRef
+  // to do so?
+  "".==[Int]
+}