[jadenfix]

Functions declared through a function typedef can panic during method code generation or static-wrapper serialization. Virtual methods can instead be emitted without their required this argument. For example, typedef int F(int); struct S { F take; }; panics, and virtual F take; produces an incorrect callable signature.

Resolve typedef/elaborated declaration types to their canonical function type before parsing the signature at the original function cursor. Ordinary function declarations keep their existing path. Added header coverage for instance/static/virtual/free functions, distinct receiver types and an alias chain, plus a C static-wrapper regression.

Fixes #3486.

Validation on main f08d4ff:

• Both new regressions fail on unchanged main; the existing stdcall control passes.
• Focused typedef suite: 27 passed.
• Compiled generated bindings and executed six Rust-to-C++ calls, including two virtual receiver cases, plus one Rust-to-C call through a generated static wrapper. All passed on macOS arm64.
• New expected bindings compile; the repository CI Clippy command, nightly formatting and diff checks pass.

Additional validation on the same PR commit:

• All 24 integration tests pass.
• Complete local header suite with libclang 17 and CLI round-trip duplication disabled: 641 passed, 1 failed (objc_template). A fresh isolated build of unchanged main fails that test with the identical generated-output diff. The earlier focused typedef checks included the normal round-trip checks.
• All reported upstream CI checks are green on this commit, including Linux amd64/arm64, macOS, generated expectations and Clippy.

Ready for maintainer review. The native E2E evidence above is from macOS arm64; the upstream matrix supplies the additional platform validation.

Prepared with OpenAI Codex assistance; no independent human review is claimed.