Fix the build.

runtime/vm/dart_api_impl_test.cc

 // Copyright (c) 2011, 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 "include/dart_api.h"
 
 #include "vm/assert.h"
 #include "vm/dart_api_impl.h"
 #include "vm/dart_api_state.h"
 #include "vm/unit_test.h"
 #include "vm/utils.h"
 #include "vm/verifier.h"
 
 namespace dart {
 
+#if defined(TARGET_ARCH_IA32)
 UNIT_TEST_CASE(Dart_Error) {
   Dart_CreateIsolate(NULL, NULL);
   Dart_EnterScope();
 
   Dart_Handle error = Dart_Error("An %s", "error");
   EXPECT(!Dart_IsValid(error));
   EXPECT_STREQ("An error", Dart_GetError(error));
 
   Dart_ExitScope();
   Dart_ShutdownIsolate();
 }
+#endif
 
 
 UNIT_TEST_CASE(Null) {
   Dart_CreateIsolate(NULL, NULL);
   Dart_EnterScope();  // Enter a Dart API scope for the unit test.
 
   Dart_Handle null = Dart_Null();
   EXPECT_VALID(null);
   EXPECT(Dart_IsNull(null));
 
@@ skipping 1937 matching lines @@
                                NULL);
     EXPECT_VALID(result);
 
     Dart_ExitScope();  // Exit the Dart API scope.
   }
   Dart_ShutdownIsolate();
 }
 #endif  // TARGET_ARCH_IA32.
 
 }  // namespace dart