* cppfiles.c (cpp_make_system_header): New function.
* cpplib.h: Prototype it.
* cpplib.c (do_line, do_pragma_system_header): Use it.
* fix-header.c (read_scan_file): Use it.
* fix-header.c (check_macro_names): Cast second arg of
cpp_defined to const unsigned char *.
(read_scan_file): Make getchar_call const unsigned char.
From-SVN: r34641
