"say $!.WHAT" in CATCH block no longer dies, but it gives Nil. The exception is
available in $_:
$ perl6-m -e '{ die 42; CATCH { say $!.WHAT; say $_.perl } }'
Nil
X::AdHoc.new(payload => 42)
42
in block <unit> at -e:1
S04/Exception handlers says "An exception handler is just a switch statement on
an implicit topic that happens to be the current exception to be dealt with.
Inside the CATCH block, the exception in question is bound to $_."
Maybe someone can clarify whether the exception should also be in $! at that
time.
