Add support for surrogates when serializing and deserializing for native ports

runtime/vm/object_test.cc

Index: runtime/vm/object_test.cc
diff --git a/runtime/vm/object_test.cc b/runtime/vm/object_test.cc
index f91f5d64aa78ca65811562971a1e68d756410ab5..9beb5fedcc9b1d693956437adad645e23d7466cc 100644
--- a/runtime/vm/object_test.cc
+++ b/runtime/vm/object_test.cc
@@ -1673,23 +1673,28 @@ TEST_CASE(StringCodePointIterator) {
                                                   "\xD7\x91\xD7\xA8"
                                                   "\xD7\x9B\xD7\x94"));
   String::CodePointIterator it2(str2);
-  EXPECT(it2.Next());
-  EXPECT_EQ(0x5D2, it2.Current());
-  EXPECT(it2.Next());
-  EXPECT_EQ(0x5DC, it2.Current());
-  EXPECT(it2.Next());
-  EXPECT_EQ(0x5E2, it2.Current());
-  EXPECT(it2.Next());
-  EXPECT_EQ(0x5D3, it2.Current());
-  EXPECT(it2.Next());
-  EXPECT_EQ(0x5D1, it2.Current());
-  EXPECT(it2.Next());
-  EXPECT_EQ(0x5E8, it2.Current());
-  EXPECT(it2.Next());
-  EXPECT_EQ(0x5DB, it2.Current());
-  EXPECT(it2.Next());
-  EXPECT_EQ(0x5D4, it2.Current());
-  EXPECT(!it2.Next());
+  int loop_count = 0;
+  while (loop_count < 3) {
+    EXPECT(it2.Next());
+    EXPECT_EQ(0x5D2, it2.Current());
+    EXPECT(it2.Next());
+    EXPECT_EQ(0x5DC, it2.Current());
+    EXPECT(it2.Next());
+    EXPECT_EQ(0x5E2, it2.Current());
+    EXPECT(it2.Next());
+    EXPECT_EQ(0x5D3, it2.Current());
+    EXPECT(it2.Next());
+    EXPECT_EQ(0x5D1, it2.Current());
+    EXPECT(it2.Next());
+    EXPECT_EQ(0x5E8, it2.Current());
+    EXPECT(it2.Next());
+    EXPECT_EQ(0x5DB, it2.Current());
+    EXPECT(it2.Next());
+    EXPECT_EQ(0x5D4, it2.Current());
+    EXPECT(!it2.Next());
+    loop_count++;
+    it2.Reset();
+  }
 
   const String& str3 = String::Handle(String::New("\xF0\x9D\x91\xA0"
                                                   "\xF0\x9D\x91\xA1"