Last snapshot bits to get working precompiled hello_world on x64.

runtime/vm/dart.cc

Index: runtime/vm/dart.cc
diff --git a/runtime/vm/dart.cc b/runtime/vm/dart.cc
index a838585dda8b87ca9d50bab6a9cb6b1364bd6cb1..b97237e4c399d7e5632819fd88f332d89c980ce3 100644
--- a/runtime/vm/dart.cc
+++ b/runtime/vm/dart.cc
@@ -141,6 +141,9 @@ const char* Dart::InitOnce(const uint8_t* vm_isolate_snapshot,
     // Now that the needed stub has been generated, set the stack limit.
     vm_isolate_->InitializeStackLimit();
     if (vm_isolate_snapshot != NULL) {
+      if (instructions_snapshot != NULL) {
+        vm_isolate_->SetupInstructionsSnapshotPage(instructions_snapshot);
+      }
       const Snapshot* snapshot = Snapshot::SetupFromBuffer(vm_isolate_snapshot);
       if (snapshot == NULL) {
         return "Invalid vm isolate snapshot seen.";
@@ -305,13 +308,18 @@ RawError* Dart::InitializeIsolate(const uint8_t* snapshot_buffer, void* data) {
   }
 
   Object::VerifyBuiltinVtables();
+#if defined(DEBUG)
+  I->heap()->Verify(kForbidMarked);
+#endif
 
   {
     TimelineDurationScope tds(I, I->GetIsolateStream(), "StubCode::Init");
     StubCode::Init(I);
   }
 
-  MegamorphicCacheTable::InitMissHandler(I);
+  if (Object::IsRunningPrecompiledCode()) {
+    MegamorphicCacheTable::InitMissHandler(I);
+  }
   if (snapshot_buffer == NULL) {
     if (!I->object_store()->PreallocateObjects()) {
       return I->object_store()->sticky_error();