indentation syntax is confused by commas in `extends` and `derives` clause

[mberndt123]

Hey,

Here's some simple code:
https://scastie.scala-lang.org/PEqZTW1YTxOOHk4L2zpzHw

trait Bar
trait Baz

def f =
  locally:
    trait Foo extends Bar, Baz

This works fine and defines a trait Foo inside that locally block.

Here's a slightly different version:
https://scastie.scala-lang.org/Tz39YMm4QG2D5PO9zbTD3w

trait Bar
trait Baz

def f =
  identity(
    locally:
      trait Foo extends Bar, Baz
  )

Here, the Scala 3.6.3 compiler reports an error: Not found: Baz

I think this is because it thinks of the comma in the extends clause as a function argument separator for the call to identity. The same problem also affects derives clauses.

[mberndt123]

Duplicate of #22527.