Bug 57762 [Dialogs] honor the platform button dismissal alignment on Mac and GTK
Button ordering is inverted on these platforms. See Display.getDismissalAlignment() or the equivalent JFace mechansim.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/dialogs/OpenResourceDialog.java
private Button openWithButton;
	/**
	 * Creates a new instance of the class.
	 * 
	 * @param parentShell
	 *            the parent shell
	 * @param container
	 *            the container
	 * @param typesMask
	 *            the types mask
	 */
	public OpenResourceDialog(Shell parentShell, IContainer container,
			int typesMask) {
		super(parentShell, true, container, typesMask);
		setTitle(IDEWorkbenchMessages.OpenResourceDialog_title);
		PlatformUI.getWorkbench().getHelpSystem().setHelp(parentShell,
				IIDEHelpContextIds.OPEN_RESOURCE_DIALOG);
	}