Make ElementLocationImpl.hashCode SMI, improve performance.

pkg/analyzer/lib/src/dart/element/element.dart

Index: pkg/analyzer/lib/src/dart/element/element.dart
diff --git a/pkg/analyzer/lib/src/dart/element/element.dart b/pkg/analyzer/lib/src/dart/element/element.dart
index 15e75ebe6d220b0c1a1677a51e3a5804715ed151..24241df84beef19222e2b07cd8f24fed4508f8e5 100644
--- a/pkg/analyzer/lib/src/dart/element/element.dart
+++ b/pkg/analyzer/lib/src/dart/element/element.dart
@@ -2250,10 +2250,10 @@ class ElementLocationImpl implements ElementLocation {
 
   @override
   int get hashCode {
-    int result = 1;
+    int result = 0;
     for (int i = 0; i < _components.length; i++) {
       String component = _components[i];
-      result = 31 * result + component.hashCode;
+      result = JenkinsSmiHash.combine(result, component.hashCode);
     }
     return result;
   }