Remove manual mixins in JFunctionN.v2.12.0-M3-dc9effe

These manual mixins were forwarding to the impl classes have
just been removed. We can now rely on default methods instead.

Update Tests:

 - Fix test/files/pos/t1237.scala, we can't have an outer field
   in an interface, always use the outer method.
 - Don't crash on meaningless trait early init fields
   test/files/neg/t2796.scala
 - Remove impl class relate parts of inner class test
 - Remove impl class relate parts of elidable test
 - Remove impl class related reflection test.
 - Remove test solely about trait impl classes renaming
 - Update check file with additional stub symbol error
 - Disable unstable parts of serialization test.
    - TODO explain, and reset the expectation

1 files changed, 2 insertions, 2 deletions

diff --git a/test/files/run/mixin-signatures.scala b/test/files/run/mixin-signatures.scala
index afd3fad877..0f6d0844d8 100644
--- a/test/files/run/mixin-signatures.scala
+++ b/test/files/run/mixin-signatures.scala
@@ -99,7 +99,7 @@ object Test {
 
   def main(args: Array[String]): Unit = {
     List(bar1, bar2, bar3, bar4, bar5) foreach show
-    List("Foo1$class", "Foo2$class") foreach show
+    List("Foo1", "Foo2") foreach show
     println(go)
   }
-}
\ No newline at end of file
+}