cppinit.c (cpp_post_options): Shut off macro expansion if -fpreprocessed.

cppinit.c (cpp_post_options): Shut off macro expansion if -fpreprocessed.

	* cppinit.c (cpp_post_options): Shut off macro expansion if
	-fpreprocessed.
	* cpplib.c (_cpp_handle_directive): If -fpreprocessed, accept
	IN_I directives only if the # is in column 1 and the directive
	name begins in column 2.
	* cppmain.c (scan_buffer): Insert a space between # and an
	identifier, when that identifier is a directive name.

	* tradcpp.c (struct file_buf): Add a pointer to the next entry
	in the header search path.
	(enum node_type): Add T_INCLUDE_NEXT.
	(directive_table): Add entry for include_next.
	(do_include_next): New function.
	(process_include): New routine, broken out of do_include.
	(finclude): Insert 'nhd' argument, to be copied into
	next_header_dir of the new buffer.
	(main): Adjust to match.
	* gsyslimits.h, limity.h: Un-indent #include_next.

testsuite:
	* gcc.dg/cpp/direct2.c: New test.
	* gcc.dg/cpp/direct2s.c: New test.

	* gcc.c-torture/execute/920730-1t.c: #undef __GNUC__ at head.

From-SVN: r41932