Use the code point iterator when computing 16-bit string hash codes.

runtime/vm/object_test.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
@@ skipping 1676 matching lines @@
   EXPECT(it3.Next());
   EXPECT_EQ(0x1D461, it3.Current());
   EXPECT(it3.Next());
   EXPECT_EQ(0x1D462, it3.Current());
   EXPECT(it3.Next());
   EXPECT_EQ(0x1D463, it3.Current());
   EXPECT(!it3.Next());
 }
 
 
+TEST_CASE(StringCodePointIteratorRange) {
+  const String& str = String::Handle(String::New("foo bar baz"));
+
+  String::CodePointIterator it0(str, 3, 0);
+  EXPECT(!it0.Next());
+
+  String::CodePointIterator it1(str, 4, 3);
+  EXPECT(it1.Next());
+  EXPECT_EQ('b', it1.Current());
+  EXPECT(it1.Next());
+  EXPECT_EQ('a', it1.Current());
+  EXPECT(it1.Next());
+  EXPECT_EQ('r', it1.Current());
+  EXPECT(!it1.Next());
+}
+
+
 TEST_CASE(GrowableObjectArray) {
   const int kArrayLen = 5;
   Smi& value = Smi::Handle();
   Smi& expected_value = Smi::Handle();
   GrowableObjectArray& array = GrowableObjectArray::Handle();
 
   // Test basic growing functionality.
   array = GrowableObjectArray::New(kArrayLen);
   EXPECT_EQ(kArrayLen, array.Capacity());
   EXPECT_EQ(0, array.Length());
@@ skipping 1524 matching lines @@
   EXPECT_NE(test1.SourceFingerprint(), test3.SourceFingerprint());
   EXPECT_NE(test3.SourceFingerprint(), test4.SourceFingerprint());
   EXPECT_NE(test4.SourceFingerprint(), test5.SourceFingerprint());
   EXPECT_NE(test5.SourceFingerprint(), test6.SourceFingerprint());
   EXPECT_EQ(test6.SourceFingerprint(), test7.SourceFingerprint());
 }
 
 #endif  // defined(TARGET_ARCH_IA32) || defined(TARGET_ARCH_X64).
 
 }  // namespace dart