Bug 65378 FindOccurencesCUEngine should use ASTProvider
RC1 FindOccurrencesEngine should get the AST from the ASTProvider so it can profit if the AST is already cached (2 occurences) e.g. JaavPlugin.getDefault().getASTProvider().getAST(cu)
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/search/FindOccurrencesEngine.java
private IClassFile fClassFile;
		
		public FindOccurencesClassFileEngine(IClassFile file, IOccurrencesFinder finder) {
			super(finder);
			fClassFile= file;
		}
		protected CompilationUnit createAST() {
			ASTParser p= ASTParser.newParser(AST.JLS2);
			p.setSource(fClassFile);
			p.setResolveBindings(true);
			return (CompilationUnit) p.createAST(null);
		}
		protected IJavaElement getInput() {
			return fClassFile;
		}
		protected IResource getMarkerOwner() {
			return fClassFile.getJavaProject().getProject();
		}
		protected void addSpecialAttributes(Map attributes) throws JavaModelException {
			attributes.put(IDE.EDITOR_ID_ATTR, JavaUI.ID_CF_EDITOR);
			JavaCore.addJavaElementMarkerAttributes(attributes, fClassFile.getType());
			attributes.put(IJavaSearchUIConstants.ATT_JE_HANDLE_ID, fClassFile.getType().getHandleIdentifier());
		}
		protected ISourceReference getSourceReference() {
			return fClassFile;
		}
	}
	private static class FindOccurencesCUEngine extends FindOccurrencesEngine {