* opts-common.c (control_warning_option): New.
	* opts.c (set_default_handlers): New.
	(decode_options): Use set_default_handlers and
	control_warning_option.
	(common_handle_option): Update call to enable_warning_as_error.
	(enable_warning_as_error): Take gcc_options parameters.  Use
	control_warning_option.
	* opts.h (set_default_handlers, control_warning_option): Declare.

c-family:
	* c-common.h (c_family_lang_mask): Declare.
	* c-opts.c (c_family_lang_mask): Make extern.
	* c-pragma.c (handle_pragma_diagnostic): Use
	control_warning_option.

testsuite:
	* gcc.dg/pragma-diag-2.c: New test.

From-SVN: r166689