The two follow-ups #2567 and #2568 left open.
A receiver declared with a leading `::` lost it: the declarator regex
started a type at a letter, so `::upb::Arena& a` inside `namespace hpb`
was looked up from `hpb` and found a namespace-local `hpb::upb::Arena`.
The declared type now keeps a leading `::` where one can stand (not after
a name, a template's arguments or a `)`, so `SkipList<Key,
Comparator>::Iterator iter` is not read as `::Iterator`), and
resolveCppAliasedType no longer takes a function-local `using Foo = Bar;`
for `::Foo`.
A lowercase outside type declared outside the calling function still used
the last-name typed match: #2413's library rule skips such declarations,
and #2567's namesake gate took capitalized types only. So a far
`absl::flat_hash_set<int> seen` linked `seen.insert(v)` to the project's
`util::flat_hash_set::insert`, and a far `std::string text` linked
`text.clear()` to a global project `string` class. The gate now covers
lowercase types, which are decided as when no class shares their name,
and cppFindsOnlyNamesakes reads a `std::` name exactly.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Colby Mchenry