Make snapshots reproducible.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index deb33653f7844c70ae9d848f5a59e62cbbe43989..761e32fa2bad05db2015aaedca786922bb4574e4 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -5322,6 +5322,17 @@ ACCESSORS(Code, handler_table, FixedArray, kHandlerTableOffset)
 ACCESSORS(Code, deoptimization_data, FixedArray, kDeoptimizationDataOffset)
 
 
+void Code::WipeOutHeader() {
+  WRITE_FIELD(this, kRelocationInfoOffset, NULL);
+  WRITE_FIELD(this, kHandlerTableOffset, NULL);
+  WRITE_FIELD(this, kDeoptimizationDataOffset, NULL);
+  // Do not wipe out e.g. a minor key.
+  if (!READ_FIELD(this, kTypeFeedbackInfoOffset)->IsSmi()) {
+    WRITE_FIELD(this, kTypeFeedbackInfoOffset, NULL);
+  }
+}
+
+
 // Type feedback slot: type_feedback_info for FUNCTIONs, stub_info for STUBs.
 void Code::InitializeTypeFeedbackInfoNoWriteBarrier(Object* value) {
   WRITE_FIELD(this, kTypeFeedbackInfoOffset, value);