Use artificial hashCode values.

pkg/analyzer/lib/src/generated/utilities_general.dart

Index: pkg/analyzer/lib/src/generated/utilities_general.dart
diff --git a/pkg/analyzer/lib/src/generated/utilities_general.dart b/pkg/analyzer/lib/src/generated/utilities_general.dart
index e62a7815e633926fe40fca86a920a24f3b26ce59..62f40293d286a7a2c6c8e935809ebd6a8944c51f 100644
--- a/pkg/analyzer/lib/src/generated/utilities_general.dart
+++ b/pkg/analyzer/lib/src/generated/utilities_general.dart
@@ -28,6 +28,8 @@ class JenkinsSmiHash {
 
   static int hash2(a, b) => finish(combine(combine(0, a), b));
 
+  static int hash3(a, b, c) => finish(combine(combine(combine(0, a), b), c));

[Brian Wilkerson, 2015/05/23 15:58:50]

Perhaps something more general would be better (although it wouldn't be as
performant):

static int hash(List<int> hashCodes) {
  int result = 0;
  for (int hashCode in hashCodes) {
    result = combine(result, hashCode);
  }
  return result;
}

+
   static int hash4(a, b, c, d) =>
       finish(combine(combine(combine(combine(0, a), b), c), d));
 }