Wrongly synthesized CanThrow for exceptions from Java stdlib

[prolativ]

Compiler version

3.1.2-RC1-bin-20211027-435207d-NIGHTLY

Minimized code

import language.experimental.saferExceptions

def foo(): Int throws ArithmeticException = 1 / 0

def test(): Unit =
  try
    foo()
  catch
    case _: ArithmeticException => println("Caught")

Output

[error] The capability to throw exception ArithmeticException is missing.
[error] The capability can be provided by one of the following:
[error]  - A using clause `(using CanThrow[ArithmeticException])`
[error]  - A `throws` clause in a result type such as `X throws ArithmeticException`
[error]  - an enclosing `try` that catches ArithmeticException
[error] 
[error] The following import might fix the problem:
[error] 
[error]   import unsafeExceptions.canThrowAny
[error] 
[error]     foo()
[error]          ^

Expectation

This should compile successfully.

When this gets compiled with -Xprint:typer, one can see that the synthesized CanThrow instance is actually

final lazy given erased val evidence$2: CanThrow[Nothing] = ???

instead of the expected CanThrow[ArithmeticException].
The same problems occurs e.g. for IndexOutOfBoundsException.