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/ProblemSeveritiesConfigurationBlock.java
private static final String SETTINGS_SECTION_NAME= null;  
	
	
	private static final Key PREF_PB_OVERRIDING_PACKAGE_DEFAULT_METHOD= getJDTCoreKey(JavaCore.COMPILER_PB_OVERRIDING_PACKAGE_DEFAULT_METHOD);
	private static final Key PREF_PB_METHOD_WITH_CONSTRUCTOR_NAME= getJDTCoreKey(JavaCore.COMPILER_PB_METHOD_WITH_CONSTRUCTOR_NAME);
	private static final Key PREF_PB_DEPRECATION= getJDTCoreKey(JavaCore.COMPILER_PB_DEPRECATION);
	private static final Key PREF_PB_DEPRECATION_IN_DEPRECATED_CODE=getJDTCoreKey(JavaCore.COMPILER_PB_DEPRECATION_IN_DEPRECATED_CODE);
	private static final Key PREF_PB_DEPRECATION_WHEN_OVERRIDING= getJDTCoreKey(JavaCore.COMPILER_PB_DEPRECATION_WHEN_OVERRIDING_DEPRECATED_METHOD);