Crash on outer.new Inner(outer) {}.

Crash on outer.new Inner(outer) {}: synthetic enclosing-instance parameter is mis-aligned with the arguments

Reproducer

public class Repro {
  class Inner {
    Inner(Repro o) {}
  }

  void test(Repro outer) {
    outer.new Inner(outer) {};
  }
}

AssertionError: numRequired 2 should equal 1 in checkArguments(
  [@H1Top @H2S2 Issue282, @H1Top @H2Top Issue282], [outer], constructor, [x0,o])

Which code crashes

A qualified new (enclosing expression written explicitly) that creates an anonymous
subclass of an inner class, where the first explicit argument has the same type as the
enclosing class, and the call is not varargs.

Removing any one of those conditions avoids the crash:

• no class body — outer.new Inner(outer); is fine (the parameter list has no x0)
• a first argument of a different type — outer.new Inner("s") {}; is fine, and so is
  outer.new Inner(null) {};
• no enclosing expression — new Inner(this) {}; inside Repro is fine (javac supplies a
  synthetic argument, so the counts match). A bare this. qualifier is enough to trigger the
  crash, though: this.new Inner(this) {}; crashes.

Only the first argument matters: outer.new Inner(outer, "s") {}; crashes as well.

There's also a test case that issues new errors in addition to the crash.

Enable framework/tests/h1h2checker/Issue282.java.