ProductN, and method synthesis toolbox.

- Finished giving case classes a ProductN parent, and flipped it on. The
"finish" part involved not breaking existing code where case classes
manually extend the appropriate ProductN. (Like, Tuple 1-22.)

- Generalized most of SyntheticMethods to ease method creation and class
manipulation in general.

- Fixed bugs related to the above, like the fact that this used to be a
compile error:

  scala> case class Foo() extends Serializable
  <console>:28: error: trait Serializable is inherited twice
         case class Foo() extends Serializable
                                  ^
It feels like there's a better way to eliminate the duplicate parents,
but after spending a lot of time chasing my tail in that peril-fraught
zone between namer and typer, I don't see an easy path to improve on
it.  Closes SI-1799.  For that modification to Typers, review by odersky.

1 files changed, 11 insertions, 0 deletions

diff --git a/test/files/pos/caseclass-parents.scala b/test/files/pos/caseclass-parents.scala
new file mode 100644
index 0000000000..d4bc52154b
--- /dev/null
+++ b/test/files/pos/caseclass-parents.scala
@@ -0,0 +1,11 @@
+case class Foo() extends Serializable
+case object Bar extends Serializable
+
+case class Bippy[T, U](x: T, y: U) extends Product2[T, U] { }
+
+case class Bounded[T <: util.Random, U <: util.Random](x: T, y: U) { }
+
+class A {
+  def f(x: Bounded[_, _]) = x.productIterator foreach g
+  def g(rand: util.Random) = ()
+}
\ No newline at end of file