diagnostics: eliminate m_ice_handler_cb [PR116613]

No functional change intended.

gcc/ChangeLog:
	PR other/116613
	* diagnostic-format-sarif.cc
	(sarif_builder::on_report_diagnostic): Move the fnotice here from
	sarif_ice_handler.
	(sarif_ice_handler): Delete.
	(diagnostic_output_format_init_sarif): Drop setting of ice handler
	callback.
	* diagnostic.cc (diagnostic_context::initialize): Likewise.
	(diagnostic_context::action_after_output): Rather than call
	m_ice_handler_cb, instead call finish on this context.
	* diagnostic.h (ice_handler_callback_t): Delete typedef.
	(diagnostic_context::set_ice_handler_callback): Delete.
	(diagnostic_context::m_ice_handler_cb): Delete.

gcc/testsuite/ChangeLog:
	PR other/116613
	* gcc.dg/plugin/diagnostic_plugin_xhtml_format.c: Update for
	removal of ICE callback.

Signed-off-by: David Malcolm <dmalcolm@redhat.com>