class X extends URL {} produces an instance with no URL state (hostname/pathname undefined), silently — explicit super(href) fails identically #10639

Found while fixing #10623 (PR #10636). Reproduces on clean main, unrelated to that PR.

class NoCtorUrl extends URL {}
const u = new NoCtorUrl("https://example.com/path");
console.log(u.hostname, u.pathname);

Node: example.com /path
Perry: undefined undefined

This is not an argument-forwarding defect. The explicit form fails identically:

class ExplicitUrl extends URL {
  constructor(href: string) { super(href); }   // same result: undefined undefined
}

That distinguishes it from #10623 (implicit ctor not forwarding to a native base) and from #10635 (rest array
over-allocated when forwarding) — the arguments arrive; the instance simply never gets URL's internal state.

Where it likely lives

crates/perry-codegen/src/lower_call/new.rs, the is_other_builtin_constructor_name /
parent_is_uncallable_builtin gate. A comment on that mechanism states in substance that Perry cannot give a
subclass instance a builtin's internal slots, so super() to such a base is a deliberate best-effort no-op — and
the observed silent-undefined, no-throw behaviour matches that exactly.

Two things to confirm before fixing: (1) that URL is literally in that matched name list (inferred from the
comment plus behaviour, not re-read); (2) the reporter's URL tests all ran inside a closure wrapper, the same
context that triggers a separate Map/Set defect — so isolate at true top level first to rule out that confound,
even though the mechanism named above reads as a compile-time, scope-independent decision.

If this really is a deliberate limitation rather than a bug, the right outcome may be a clear thrown error
instead of silently producing an object with undefined everywhere.