The generic-parent support (#1511) emitted a spurious references/generic_arg edge
(and a sourceless stub node) for a bare type parameter — the T in
`class Box<T> extends Container<T>` — because the Java extractor had no type-
parameter tracking. _java_collect_type_refs now collects the in-scope type-
parameter names (walking class/interface/record/method/constructor declarations,
including bounded and multiple params) and skips references to them, while keeping
every real type. Scoped to the declaring node, so a real class that shares a name
with a type parameter elsewhere is still referenced.
Ported from PR #1518 by @oleksii-tumanov. Closes the nit flagged when #1511 landed.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
