Enable remaining execution tests on x64.

runtime/vm/debugger_api_impl_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 "include/dart_debugger_api.h"
 #include "platform/assert.h"
 #include "vm/unit_test.h"
 
 namespace dart {
 
-#if defined(TARGET_ARCH_IA32)  // Only ia32 can run execution tests.
-
+// Only ia32 and x64 can run execution tests.
+#if defined(TARGET_ARCH_IA32) || defined(TARGET_ARCH_X64)
 
 static bool breakpoint_hit = false;
 
 static const bool verbose = false;
 
 #define EXPECT_NOT_ERROR(handle)                                              \
   if (Dart_IsError(handle)) {                                                 \
     OS::Print("Error: %s\n", Dart_GetError(handle));                          \
   }                                                                           \
   EXPECT(!Dart_IsError(handle));
@@ skipping 51 matching lines @@
   breakpoint_hit = false;
   Dart_Handle retval = Dart_InvokeStatic(lib,
                            Dart_NewString(""),
                            Dart_NewString("main"),
                            0,
                            NULL);
   EXPECT(!Dart_IsError(retval));
   EXPECT(breakpoint_hit == true);
 }
 
-#endif  // TARGET_ARCH_IA32.
+#endif  // defined(TARGET_ARCH_IA32) || defined(TARGET_ARCH_X64).
 
 }  // namespace dart