Add framework support for darwin.

Add framework support for darwin.

	* c-incpath.c: Include target.h and machmode.h.
	(add_path): Use a consistent style for cpp_dir.  Initialize
	p->construct to 0.
	(add_cpp_dir_path): New.
	(register_include_chains): Add use of extra_includes callback.
	(hook_void_int): Add.
	(target_c_incpath): Add.
	* c-incpath.h (add_cpp_dir_path): New.
	(target_c_incpath_s): Add.
	(target_c_incpath): Add.
	(C_INCPATH_INIT): Add.
	* c-opts.c (c_common_missing_argument,
	c_common_handle_option): Add -F argument processing.
	* c.opt: Add -F argument processing.
	* gcc.c (trad_capable_cpp): Add -F argument processing.
	* cppfiles.c (find_file_in_dir): Update to use construct
	callback.
	(search_path_exhausted, cpp_get_path, cpp_get_buffer,
	cpp_get_prev): New.
	(_cpp_find_file): Use search_path_exhausted.
	(make_cpp_dir): Initialize construct to 0.
	* cpplib.h (missing_header_cb
	cpp_get_path, cpp_get_buffer, cpp_get_file, cpp_get_prev): New.
	(cpp_callbacks): Add missing_header
	(cpp_dir): Add construct.
	* target-def.h: (TARGET_OPTF): New.
	* hooks.c (hook_void_int, hook_void_charptr): Add.
	* hooks.h (hook_void_int, hook_void_charptr): Add.
	* Makefile.in (c-incpath.o) : Add $(TARGET_H) and
	$(MACHMODE_H) dependencies.
	* doc/invoke.texi (Darwin Options): Document -F.
	* doc/tm.texi (TARGET_EXTRA_INCLUDES): Add.
	(TARGET_OPTF): Add.
	* fix-header.c (target_c_incpath): Add.

	* config/darwin-c.c: Add c-incpath.h include.
	(using_frameworks, find_subframework_file,
	find_subframework_header, add_system_framework_path,
	frameworks_in_use, num_frameworks, max_frameworks,
	add_framework, find_framework, struct framework_header,
	framework_header_dirs, framework_construct_pathname,
	find_subframework_file, add_system_framework_path,
	add_framework_path, framework_defaults,
	darwin_register_frameworks, find_subframework_header): Add.
	* config/darwin.h (TARGET_EXTRA_INCLUDES, TARGET_OPTF): New.
	(TARGET_OPTION_TRANSLATE_TABLE): Add -framework support.
	(CPP_SPEC): Add __APPLE_CC__ support.
	* t-darwin (darwin-c.o): Add c-incpath.h dependency.

From-SVN: r78875