C typedef alias to struct loses record id

• Type: bug (Track A+C — C parser typedef metadata)
• Status: done
• Owner: Codex
• Found / Opened: 2026-06-27, while switching make test-lua from stdin to luaL_loadfile after the crtl fopen bridge landed.

Symptom

Lua's file-handle type is a two-step typedef:

typedef struct luaL_Stream { FILE *f; lua_CFunction closef; } luaL_Stream;
typedef luaL_Stream LStream;

The second typedef (typedef luaL_Stream LStream;) kept only tyRecord and dropped the original record id. Later LStream *p; p->closef therefore resolved with REC_NONE, so field lookup collapsed to offset 0. Lua's close path loaded the FILE *f slot as the callback and jumped through garbage during f:close() / lua_close.

Fix

Preserve typedef metadata when aliasing typedefs in ParseCTypedef:

• record aliases keep CTypeBaseRec;
• pointer aliases keep pointed-at type/record metadata even when the alias does not spell a fresh *;
• function-pointer typedef aliases keep their call signature.

Log

• 2026-06-27 — Fixed in compiler/cparser.inc. Regression: test/ctypedef_alias_fnptr_field_b89.c. Broader proof: make test-lua now loads scripts via luaL_loadfile, and test/lua/files.lua covers Lua io.open read/write/seek/close over crtl stdio. Gate: make test green.