fix JavaMethodType creation and parameter matching of JavaMethodTypes

Fixes two bugs needed for java-override test:

Namer was creating a MethodType instead of a JavaMethodType even though
the JavaDefined flag was set on the DefDef.

TypeComparer.matchingParams had the cases mixed up: it considered a
j.l.Object in Scala code to match a s.Any in Java code. It should be
that Object in Java code matches Any in Scala code.

Author: olhotak

src/dotty/tools/dotc/core/TypeComparer.scala

@@ -681,8 +681,8 @@ class TypeComparer(initctx: Context) extends DotClass with ConstraintHandling wi
       formals2 match {
         case formal2 :: rest2 =>
           (isSameType(formal1, formal2)
-            || isJava1 && (formal2 isRef ObjectClass) && (formal1 isRef AnyClass)
-            || isJava2 && (formal1 isRef ObjectClass) && (formal2 isRef AnyClass)) &&
+            || isJava1 && (formal1 isRef ObjectClass) && (formal2 isRef AnyClass)
+            || isJava2 && (formal2 isRef ObjectClass) && (formal1 isRef AnyClass)) &&
           matchingParams(rest1, rest2, isJava1, isJava2)
         case nil =>
           false

src/dotty/tools/dotc/typer/Namer.scala

@@ -656,6 +656,7 @@ class Namer { typer: Typer =>
         (paramSymss :\ restpe1) { (params, restpe) =>
           val make =
             if (params.nonEmpty && (params.head is Implicit)) ImplicitMethodType
+            else if(ddef.mods is JavaDefined) JavaMethodType
             else MethodType
           make.fromSymbols(params, restpe)
         }

test/dotc/tests.scala

@@ -57,6 +57,7 @@ class tests extends CompilerTest {
   @Test def pos_packageobject() = compileFile(posDir, "packageobject")
   @Test def pos_overloaded() = compileFile(posDir, "overloaded")
   @Test def pos_overrides() = compileFile(posDir, "overrides")
+  @Test def pos_javaOverride() = compileDir(posDir + "java-override")
   @Test def pos_templateParents() = compileFile(posDir, "templateParents")
   @Test def pos_structural() = compileFile(posDir, "structural")
   @Test def pos_overloadedAccess = compileFile(posDir, "overloadedAccess")