First step towards splitting a full snapshot into a vm isolate snapshot and a

runtime/vm/dart.cc

Index: runtime/vm/dart.cc
===================================================================
--- runtime/vm/dart.cc	(revision 44745)
+++ runtime/vm/dart.cc	(working copy)
@@ -75,7 +75,8 @@
 };
 
 
-const char* Dart::InitOnce(Dart_IsolateCreateCallback create,
+const char* Dart::InitOnce(const uint8_t* vm_isolate_snapshot,
+                           Dart_IsolateCreateCallback create,
                            Dart_IsolateInterruptCallback interrupt,
                            Dart_IsolateUnhandledExceptionCallback unhandled,
                            Dart_IsolateShutdownCallback shutdown,
@@ -138,6 +139,9 @@
       return "SSE2 is required.";
     }
 #endif
+    if (vm_isolate_snapshot != NULL) {
+      FATAL("Initializing the VM isolate from a snapshot is not implemented\n");
+    }
     Object::FinalizeVMIsolate(vm_isolate_);
   }
   // There is a planned and known asymmetry here: We enter one scope for the VM