[vm] Change TypedData_getUint64 native method to silently cast values

tests/corelib_2/typed_data_with_limited_ints_test.dart

Index: tests/corelib_2/typed_data_with_limited_ints_test.dart
diff --git a/tests/corelib_2/typed_data_with_limited_ints_test.dart b/tests/corelib_2/typed_data_with_limited_ints_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..934e246d43fe8b1869c97d6a9cce1b5b0108650b
--- /dev/null
+++ b/tests/corelib_2/typed_data_with_limited_ints_test.dart
@@ -0,0 +1,49 @@
+// Copyright (c) 2017, 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.
+// VMOptions=--limit-ints-to-64-bits --optimization_counter_threshold=10 --no-background-compilation
+
+// Test for dart:typed_data (in particular, ByteData.get/setUint64 and
+// UInt64List) in --limit-ints-to-64-bits mode (with limited 64-bit integers).
+
+import 'dart:typed_data';
+import "package:expect/expect.dart";
+
+testByteData() {
+  ByteData data = new ByteData(17);
+
+  data.setInt64(5, -0x1122334455667788);
+  Expect.equals(-0x1122334455667788, data.getUint64(5));
+
+  data.setUint32(5, 0x10203040);
+  Expect.equals(0x10203040aa998878, data.getUint64(5));
+
+  data.setUint64(3, -1);
+  Expect.equals(-1, data.getInt64(3));
+
+  data.setUint64(7, 0x7fedcba987654321);
+  Expect.equals(0x7fedcba987654321, data.getInt64(7));
+}
+
+testUint64List() {
+  Uint64List u64 = new Uint64List(3);
+  Int64List i64 = new Int64List.view(u64.buffer);
+
+  i64[0] = 0x7fffffffffffffff;
+  i64[1] = -1;
+  i64[2] = 42;
+
+  Expect.equals(0x7fffffffffffffff, u64[0]);
+  Expect.equals(-1, u64[1]);
+  Expect.equals(42, u64[2]);
+
+  u64[0] = -900000000000000;
+  Expect.equals(-900000000000000, i64[0]);
+}
+
+main() {
+  for (int i = 0; i < 20; i++) {
+    testByteData();
+    testUint64List();
+  }
+}