Bug 123786 Following bug 109980, the compliance 6.0 should be added to the compiler's compliance list.
If the JRE/JDK used is a 1.6/6.0 VM, then the compliance 6.0 should be available. Compliance 1.6 implies source level 1.6 and target level 1.6.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/ComplianceConfigurationBlock.java
return;
			}
		} else {
			updateComplianceEnableState();
			updateAssertEnumAsIdentifierEnableState();
			updateInlineJSREnableState();
			fComplianceStatus= validateCompliance();
			validateJRE50Status();
		}		
		fContext.statusChanged(fComplianceStatus);
	}
	
	private void validateJRE50Status() {
		if (fJRE50InfoText != null && !fJRE50InfoText.isDisposed()) {
			boolean isVisible= false;
			String compliance= getStoredValue(PREF_COMPLIANCE); 
			if (VERSION_1_5.equals(compliance)) {
				if (fProject != null) { 
					try {
						IVMInstall install= JavaRuntime.getVMInstall(JavaCore.create(fProject));
						isVisible= (install == null) || !BuildPathSupport.hasMatchingCompliance(install, VERSION_1_5);
					} catch (CoreException e) {
						JavaPlugin.log(e);
					}
				} else {
					IVMInstall defaultVMInstall= JavaRuntime.getDefaultVMInstall();
					isVisible= (defaultVMInstall == null) || !BuildPathSupport.hasMatchingCompliance(defaultVMInstall, VERSION_1_5);
				}
			}
			fJRE50InfoText.setVisible(isVisible);