fix #9324: forbid no-arg java.lang.Enum ctor

[bishabosha]

pretend the no-arg constructor does not exist unless called from an enum parent

[smarter]

Why is this not forbidden by default?

[bishabosha]

Why is this not forbidden by default?

good point- will adjust

[bishabosha]

so now there is just an extra error in the case where it was possible to call the no arg ctor, which basically only ever could happen in migration mode

[bishabosha]

this still doesn't deal with this:

// running repl with -source:3.0-migration
scala> final class C extends jl.Enum[C]("N")                                                                         
1 |final class C extends jl.Enum[C]("N")
  |                      ^^^^^^^^^^
  |None of the overloaded alternatives of constructor Enum in class Enum with types
  | [E <: Enum[LazyRef(E)]](x$0: String, x$1: Int): Enum[E]
  | [E <: Enum[LazyRef(E)]](): Enum[E]
  |match arguments (("N" : String))

do we want the other thing to never exist in overload errors?, and files can locally import a language mode for source so we can't patch it in Definitions

[smarter]

If it's only temporary for migration the overload error message is fine