Adds Runtime call stub and Dart entry stub to ARM64.

runtime/vm/snapshot_test.cc

Index: runtime/vm/snapshot_test.cc
===================================================================
--- runtime/vm/snapshot_test.cc	(revision 35155)
+++ runtime/vm/snapshot_test.cc	(working copy)
@@ -2,9 +2,7 @@
 // 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.
 
-// TODO(zra): Remove when tests are ready to enable.
 #include "platform/globals.h"
-#if !defined(TARGET_ARCH_ARM64)
 
 #include "include/dart_debugger_api.h"
 #include "platform/assert.h"
@@ -836,6 +834,9 @@
 };
 
 
+// TODO(zra): Remove when tests are ready to enable.
+#if !defined(TARGET_ARCH_ARM64)
+
 static void GenerateSourceAndCheck(const Script& script) {
   // Check if we are able to generate the source from the token stream.
   // Rescan this source and compare the token stream to see if they are
@@ -2718,6 +2719,6 @@
   Dart_ExitScope();
 }
 
+#endif  // !defined(TARGET_ARCH_ARM64)
+
 }  // namespace dart
-
-#endif  // !defined(TARGET_ARCH_ARM64)