bug: parse error on `extern "C" using foobar = void (*)(void);`

Did you check existing issues?

• I have read all the tree-sitter docs if it relates to using the parser
• I have searched the existing issues of tree-sitter-cpp

Tree-Sitter CLI Version, if relevant (output of tree-sitter --version)

0.25.1

Describe the bug

tree-sitter-cpp does not understand an extremely obscure using declaration: extern "C" on function pointer type alias declarations, for strict correctness in not mixing linkage; though I think most compilers do not care because programmers are way too sloppy to get away with enforcing it.

extern "C" using NixPluginEntry = void (*)();

Compiles successfully with clang++ -std=c++23 -c test.cpp.

Steps To Reproduce/Bad Parse Tree

Apply this patch to your tree-sitter-cpp:

diff --git a/test/corpus/declarations.txt b/test/corpus/declarations.txt
index acaf288..d0dec09 100644
--- a/test/corpus/declarations.txt
+++ b/test/corpus/declarations.txt
@@ -106,6 +106,8 @@ using a = typename b<T>::c;
 using foobar [[deprecated]] = int;
 using foobar [[deprecated]] [[maybe_unused]] = int;
 
+extern "C" using foobar = void (*)(void);
+
 --------------------------------------------------------------------------------
 
 (translation_unit

Run tree-sitter test.

Obtain parse failure:

      (linkage_specification
        (string_literal
          (string_content))
        (declaration
          (type_identifier)
          (init_declarator
            (identifier)
            (call_expression
              (call_expression
                (primitive_type)
                (argument_list
                  (ERROR)))
              (argument_list
                (ERROR
                  (primitive_type))))))))

Expected Behavior/Parse Tree

I don't know what the parse tree should look like, I just know the highlight broke and there should not be ERROR nodes in there.

Repro

extern "C" using foobar = void (*)(void);

Start with test/corpus/declarations.txt, add the supplied reproduction, and run tree-sitter test to inspect the failing parse. Trace how the C++ grammar handles extern "C" and using declarations; done means this case parses without ERROR nodes and the regression test passes.