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/JavaSearchPage.java
break;
			case IJavaElement.PACKAGE_FRAGMENT_ROOT:
				searchFor= PACKAGE;
				limitTo= REFERENCES;
				pattern= element.getElementName();
				break;
			case IJavaElement.PACKAGE_DECLARATION:
				searchFor= PACKAGE;
				limitTo= REFERENCES;
				pattern= element.getElementName();
				break;
			case IJavaElement.IMPORT_DECLARATION:
				pattern= element.getElementName();
				IImportDeclaration declaration= (IImportDeclaration)element;
				if (declaration.isOnDemand()) {
					searchFor= PACKAGE;
					int index= pattern.lastIndexOf('.');
					pattern= pattern.substring(0, index);
				} else {
					searchFor= TYPE;
				}
				limitTo= DECLARATIONS;
				break;
			case IJavaElement.TYPE:
				searchFor= TYPE;
				limitTo= REFERENCES;
				pattern= JavaModelUtil.getFullyQualifiedName((IType)element);
				break;
			case IJavaElement.COMPILATION_UNIT:
				ICompilationUnit cu= (ICompilationUnit)element;