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/wizards/buildpaths/BuildPathSupport.java
CPListElement newElem= CPListElement.createFromExisting(updatedEntry, jproject);
		for (int i= 0; i < updatedAttributes.length; i++) {
			String attrib= updatedAttributes[i];
			currElem.setAttribute(attrib, newElem.getAttribute(attrib));
		}
		return currElem.getClasspathEntry();
	}
	/**
	 * Request a container update.
	 * @param jproject The project of the container
	 * @param container The container to requesta  change to
	 * @param newEntries The updated entries
	 * @throws CoreException
	 */
	public static void requestContainerUpdate(IJavaProject jproject, IClasspathContainer container, IClasspathEntry[] newEntries) throws CoreException {
		IPath containerPath= container.getPath();
		IClasspathContainer updatedContainer= new UpdatedClasspathContainer(container, newEntries);
		ClasspathContainerInitializer initializer= JavaCore.getClasspathContainerInitializer(containerPath.segment(0));
		if (initializer != null) {
			initializer.requestClasspathContainerUpdate(containerPath, jproject, updatedContainer);
		}
	}
	private static void updateProjectClasspath(Shell shell, IJavaProject jproject, IClasspathEntry newEntry, String[] changedAttributes, IProgressMonitor monitor) throws JavaModelException {
		IClasspathEntry[] oldClasspath= jproject.getRawClasspath();
		int nEntries= oldClasspath.length;
		ArrayList newEntries= new ArrayList(nEntries + 1);
		int entryKind= newEntry.getEntryKind();
		IPath jarPath= newEntry.getPath();
		boolean found= false;
		for (int i= 0; i < nEntries; i++) {