Root cause: gnulib configure bakes raw typedef statements
(typedef long unsigned int size_t; etc.) into the generated
Makefile's GL_CFLAG_GNULIB_WARNINGS variable. These break
shell command parsing when expanded on recipe lines.
Fix:
1. Strip raw typedefs from all generated Makefiles after configure
2. Provide fix_types.h with guarded typedefs for size_t, ptrdiff_t,
off_t, wchar_t, ssize_t, time_t
3. Force-include fix_types.h via CPPFLAGS to work around the
cross-compiler's GCC built-in stddef.h ordering issue
Also: comprehensive upstream relibc comparison and import plan
vasilito
b1e83ae89a