7cfef2633e
The cross-compiler's GCC built-in stddef.h is blocked by relibc's _STDDEF_H guard, causing size_t/off_t/ptrdiff_t to be undefined. Add fix_types.h with guarded typedefs and force-include via CPPFLAGS. Also: comprehensive upstream relibc comparison for systematic import. Remaining: redoxer env overrides CC, injecting broken stdint typedefs from its toolchain. This needs a redoxer-level fix to clean the injected flags before passing to build commands.