Traits in package have an initial method with an illegal method name

[smarter]

package foo {
  trait Bar
}

% javap -c foo/Bar
Compiled from "tp.scala"
public interface foo.Bar {
  public foo.Bar initial$foo.Bar();
    Code:
       0: aload_0
       1: areturn

Note that the method contains a '.' which is not allowed:

java.lang.ClassFormatError: Illegal method name "initial$foo.Bar" in class foo/Bar

[smarter]

This is because TraitConstructors calls fullName, it could be replaced by fullNameSeparated.

[smarter]

Note that using fullNameSeparated("$") the method becomes initial$fooBar and not initial$foo$Bar, because of the special case:

if (owner.is(ModuleClass) && sep == "$") sep = "" // duplicate scalac's behavior: don't write a double '$$' for module class members.

[smarter]

Needef for tests/pending/run/Meter.scala.