re PR preprocessor/6517 (gcc hangs on C compile with multiple "-I-")

re PR preprocessor/6517 (gcc hangs on C compile with multiple "-I-")

	PR preprocessor/6517
	* Makefile.in: Update.
	* c-common.c (c_common_post_options): Add preprocessor
	errors to the error count.
	* c-lang.c (c_post_options): Kill.
	(LANG_HOOKS_POST_OPTIONS): Use c_common_post_options.
	* hooks.h: Add header guards.
	* langhooks-def.h: Include hooks.h.
	(LANG_HOOKS_POST_OPTIONS): Update.
	* langhooks.h (struct lang_hooks): Update post_options.
	* toplev.c (parse_options_and_default_flags): Update.
cp:
	* cp-lang.c (LANG_HOOKS_POST_OPTIONS): Use c_common_post_options.
	* cp-tree.h (cxx_post_options): Kill.
	* cp-lex.c (cxx_post_options): Kill.
objc:
	* objc-lang.c (objc_post_options): Kill.
	(LANG_HOOKS_POST_OPTIONS): Use c_common_post_options.

From-SVN: r53724