Bug 5231 Add search for field read and write references
The UI should support the following new JDT Core feature: Search for field read and field write references. Two new constants have been added on IJavaSearchConstants to be used when creating a field reference search pattern: - READ_REFERENCES: the search results contain *only* read access to a field. - WRITE_REFERENCES: the search results contain *only* write access to a field. If REFERENCES is used, then search results contain both read and write accesss to a field.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/search/JavaSearchOperation.java
this(workspace, limitTo, scope, scopeDescription, collector);
		fElementPattern= pattern;
	}
	
	public JavaSearchOperation(
				IWorkspace workspace,
				String pattern,
				int searchFor, 
				int limitTo,
				IJavaSearchScope scope,
				String scopeDescription,
				JavaSearchResultCollector collector) {
		this(workspace, limitTo, scope, scopeDescription, collector);
		fStringPattern= pattern;
		fSearchFor= searchFor;
	}
	
	protected void execute(IProgressMonitor monitor) throws CoreException {
		fCollector.setProgressMonitor(monitor);
		SearchEngine engine= new SearchEngine();
		if (fElementPattern != null)
			engine.search(fWorkspace, fElementPattern, fLimitTo, fScope, fCollector);
		else
			engine.search(fWorkspace, fStringPattern, fSearchFor, fLimitTo, fScope, fCollector);
	}
	String getDescription() {
		String desc= null;
		if (fElementPattern != null) {
			if (fLimitTo == IJavaSearchConstants.REFERENCES
			&& fElementPattern.getElementType() == IJavaElement.METHOD)