When creating a JIT app snapshot, don't recreate the VM isolate snapshot.

runtime/vm/stub_code.h

 // 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.
 
 #ifndef RUNTIME_VM_STUB_CODE_H_
 #define RUNTIME_VM_STUB_CODE_H_
 
 #include "vm/allocation.h"
 #include "vm/assembler.h"
 
 namespace dart {
 
 // Forward declarations.
 class Code;
 class Isolate;
 class ObjectPointerVisitor;
 class RawCode;
 class SnapshotReader;
 class SnapshotWriter;
-class Serializer;
-class Deserializer;
 
 // List of stubs created in the VM isolate, these stubs are shared by different
 // isolates running in this dart process.
 #if !defined(TARGET_ARCH_DBC)
 #define VM_STUB_CODE_LIST(V)                                                   \
   V(GetStackPointer)                                                           \
   V(JumpToFrame)                                                               \
   V(RunExceptionHandler)                                                       \
   V(DeoptForRewind)                                                            \
   V(UpdateStoreBuffer)                                                         \
@@ skipping 86 matching lines @@
 };
 
 
 // class StubCode is used to maintain the lifecycle of stubs.
 class StubCode : public AllStatic {
  public:
   // Generate all stubs which are shared across all isolates, this is done
   // only once and the stub code resides in the vm_isolate heap.
   static void InitOnce();
 
-  static void Push(Serializer* serializer);
-  static void WriteRef(Serializer* serializer);
-  static void ReadRef(Deserializer* deserializer);
-
   // Generate all stubs which are generated on a per isolate basis as they
   // have embedded objects which are isolate specific.
   static void Init(Isolate* isolate);
 
   static void VisitObjectPointers(ObjectPointerVisitor* visitor);
 
   // Returns true if stub code has been initialized.
   static bool HasBeenInitialized();
 
   // Check if specified pc is in the dart invocation stub used for
   // transitioning into dart code.
   static bool InInvocationStub(uword pc);
 
   // Check if the specified pc is in the jump to frame stub.
   static bool InJumpToFrameStub(uword pc);
 
   // Returns NULL if no stub found.
   static const char* NameOfStub(uword entry_point);
 
 // Define the shared stub code accessors.
 #define STUB_CODE_ACCESSOR(name)                                               \
-  static const StubEntry* name##_entry() { return name##_entry_; }             \
+  static const StubEntry* name##_entry() { return entries_[k##name##Index]; }  \
   static intptr_t name##Size() { return name##_entry()->Size(); }
   VM_STUB_CODE_LIST(STUB_CODE_ACCESSOR);
 #undef STUB_CODE_ACCESSOR
 
   static RawCode* GetAllocationStubForClass(const Class& cls);
 
   static const StubEntry* UnoptimizedStaticCallEntry(intptr_t num_args_tested);
 
   static const intptr_t kNoInstantiator = 0;
 
+  static StubEntry* EntryAt(intptr_t index) { return entries_[index]; }
+  static void EntryAtPut(intptr_t index, StubEntry* entry) {
+    entries_[index] = entry;
+  }
+  static intptr_t NumEntries() { return kNumStubEntries; }
+
  private:
   friend class MegamorphicCacheTable;
 
   static const intptr_t kStubCodeSize = 4 * KB;
 
 #define STUB_CODE_GENERATE(name)                                               \
   static void Generate##name##Stub(Assembler* assembler);
-  VM_STUB_CODE_LIST(STUB_CODE_GENERATE);
+  VM_STUB_CODE_LIST(STUB_CODE_GENERATE)
 #undef STUB_CODE_GENERATE
 
-#define STUB_CODE_ENTRY(name) static StubEntry* name##_entry_;
-  VM_STUB_CODE_LIST(STUB_CODE_ENTRY);
+  enum {
+#define STUB_CODE_ENTRY(name) k##name##Index,
+    VM_STUB_CODE_LIST(STUB_CODE_ENTRY)
 #undef STUB_CODE_ENTRY
+        kNumStubEntries
+  };
+
+  static StubEntry* entries_[kNumStubEntries];
 
   // Generate the stub and finalize the generated code into the stub
   // code executable area.
   static RawCode* Generate(const char* name,
                            void (*GenerateStub)(Assembler* assembler));
 
   static void GenerateMegamorphicMissStub(Assembler* assembler);
   static void GenerateAllocationStubForClass(Assembler* assembler,
                                              const Class& cls);
   static void GenerateNArgsCheckInlineCacheStub(
@@ skipping 12 matching lines @@
 
 // Zap value used to indicate unused CODE_REG in deopt.
 static const uword kZapCodeReg = 0xf1f1f1f1;
 
 // Zap value used to indicate unused return address in deopt.
 static const uword kZapReturnAddress = 0xe1e1e1e1;
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_STUB_CODE_H_