bug: Package of unqualified type name in catch not marked as implicit

[slarse]

Given a try/catch like so:

try {
} catch (RuntimeException e) {
}

The package of the exception type is not marked as implicit. A side-effect of this is that the type name is printed fully qualified during pretty-printing, like so:

try {
} catch (java.lang.RuntimeException e) {
}

This is related to #3268, #3372, #3373