enum inside macro impl

[rnd4222]

Minimized code

    enum T:
      case N
      case C(i: Int, t: T)
    T.C(1, T.C(2, T.N))

Output

[error]    |  Exception occurred while executing macro expansion.
[error]    |  java.lang.StackOverflowError

Expectation

When this example is defined in a regular code, it works fine.
When used inside of a macro implementation, it causes StackOverflow.
Workaround is to replace case N with case N() or replace enum with a sealed trait hierarchy.

[bishabosha]

reproduced in REPL with this code:

import quoted._

inline def someMacro: Any = ${ someMacroImpl }

def someMacroImpl(using QuoteContext): Expr[Any] = {
  enum T:
    case N
    case C(i: Int, t: T)
  T.C(1, T.C(2, T.N))
  '{null}
}

scala> someMacro                                                                                                        
1 |someMacro
  |^^^^^^^^^
  |Exception occurred while executing macro expansion.
  |java.lang.StackOverflowError
  |
  | This location contains code that was inlined from rs$line$4:1

[bishabosha]

this is due to a local enum in a method:

def foo: Any = {
   enum T:
     case N
     case C(i: Int, t: T)
   T.C(1, T.C(2, T.N))
   null
 }

this has an infinite loop in the construction of object T

[bishabosha]

this is already fixed in #9677