Bug 63840 warning on unused labels
we have warnings for all sorts of unused things. one for unused labels would be good too.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/PreferencesMessages.java
public static String ProblemSeveritiesConfigurationBlock_pb_undocumented_empty_block_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_unused_throwing_exception_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_unused_throwing_exception_when_overriding_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_missing_serial_version_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_overriding_pkg_dflt_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_method_naming_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_no_effect_assignment_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_incompatible_interface_method_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_indirect_access_to_static_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_hidden_catchblock_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_static_access_receiver_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_unused_imports_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_unused_local_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_unused_parameter_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_signal_param_in_overriding_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_unused_private_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_non_externalized_strings_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_deprecation_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_deprecation_in_deprecation_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_deprecation_when_overriding_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_empty_statement_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_unnecessary_type_check_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_incomplete_enum_switch_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_inconsistent_null_check_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_unnecessary_else_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_synth_access_emul_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_autoboxing_problem_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_char_array_in_concat_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_missing_override_annotation_label;
	public static String ProblemSeveritiesConfigurationBlock_pb_missing_deprecated_annotation_label;