cppexp.c (lex): Don't assume tokens are NUL terminated.

cppexp.c (lex): Don't assume tokens are NUL terminated.

	* cppexp.c (lex): Don't assume tokens are NUL terminated.
	* cpplib.c (do_include, do_import, do_include_next,
	read_line_number, detect_if_not_defined): Likewise.
	* cpphash.c (collect_expansion): Likewise.
	(special_symbol, _cpp_macroexpand): Check return from
	cpp_file_buffer.
	* cpphash.h (CPP_NUL_TERMINATE, CPP_NUL_TERMINATE_Q): Delete
	macros.  Delete all uses.

	* gcc.dg/cpp-mi.c: Add two more test cases.
	* gcc.dg/cpp-mind.h, gcc.dg/cpp-mindp.h: New files.

From-SVN: r33223