Improved function entry hook coverage

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
old mode 100644
new mode 100755
index a51a9b117e7a1969acb146e047175eaf1ac4740e..f65e4662035684c84acab61691cec88ef4f543bd
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -2574,7 +2574,13 @@ Genesis::Genesis(Isolate* isolate,
   StackLimitCheck check(isolate);
   if (check.HasOverflowed()) return;
 
-  native_context_ = Snapshot::NewContextFromSnapshot();
+  // We can only de-serialize a context if the isolate was initialized from
+  // a snapshot. Otherwise we have to build the context from scratch.
+  if (isolate->initialized_from_snapshot())
+    native_context_ = Snapshot::NewContextFromSnapshot();
+  else
+    native_context_ = Handle<Context>();
+
   if (!native_context().is_null()) {
     AddToWeakNativeContextList(*native_context());
     isolate->set_context(*native_context());