* cppfiles.c (stack_include_file): Don't optimize zero-length

	* cppfiles.c (stack_include_file): Don't optimize zero-length
	files.
	(read_include_file): NUL-terminate read files.
	* cpplex.c (handle_newline, skip_escaped_newlines,
	get_effective_char, skip_whitespace, parse_identifier,
	parse_identifier_slow, parse_number, parse_string,
	_cpp_lex_direct): Optimize for the fact that buffers are guaranteed
	NUL-terminated.
	* cpplib.c (destringize_and_run, cpp_define, handle_assertion):
	Be sure buffers are NUL terminated.
	* cppmacro.c (warn_of_redefinition): Kill compile warning.

	* c-common.c: Include tree-inline.h.
	(c_language): Move separate definitions here.
	(c_common_init_options, c_common_post_options): New.
	(c_common_lang_init): Rename c_common_init.
	* c-common.h (c_common_lang_init): Similarly.
	(c_common_init_options, c_common_post_options): New.
	* c-lang.c (c_post_options): Move body to c_common_post_options.
	(c_init_options): Use c_common_init_options.
	(c_init): Update.
	* langhooks.def: Rearrange.
	* langhooks.h: Rearrange, and improve comments.
	* toplev.c (do_compile): New function.
	(toplev_main): Use it.
	(lang_independent_f_options, parse_options_and_default_flags,
	process_options): Remove trailing periods.
	* Makefile.in: Update.
cp:	* decl2.c (c_language): Move to c-common.c.
	* lex.c (cxx_post_options, cxx_init_options): Use c-common.c
	functions.
	(cxx_init): Update.
objc:	* objc-act.c (objc_post_options, objc_init_options): Use c-common.c
	functions.
	(ojbc_init): Update.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@47362 138bc75d-0d04-0410-961f-82ee72b054a4