Type named `$` is replaced by empty string in error messages

Compiler version

3.1.3-RC2

Minimized code

case class $[A](value: A)

def f(x: Int): Unit = {}

f(T(3))

Output

Found:   [Int]
Required: Int

Notice the missing $.

Expectation

Found:    $[Int]
Required: Int

[nicolasstucki]

The best thing we could do is to identify names containing $ and emit a warning. Most users do not know that these names are reserved for compiler generated code.

[som-snytt]

The issue about accessing Scala MODULE$ from Java makes me think messages should never strip dollar in a Java context.

7 |import bar.slf4j.ScalaMDCAdapter$;
  |                 ^
  |                 value ScalaMDCAdapter is not a member of bar.slf4j - did you mean slf4j.ScalaMDCAdapter?

https://github.com/lampepfl/dotty/issues/15608