[interpreter] Add ability to preserve bytecode.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index bf6ad3d4d7a3ee08a516a967f1687031530975e9..101d3ec7099f6410f86946ddc7685ab444d3438d 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -6894,6 +6894,7 @@ class SharedFunctionInfo: public HeapObject {
   inline AbstractCode* abstract_code();
 
   inline void ReplaceCode(Code* code);
+  inline bool HasBaselineCode() const;
 
   // [optimized_code_map]: Map from native context to optimized code
   // and a shared literals array.
@@ -6980,7 +6981,7 @@ class SharedFunctionInfo: public HeapObject {
   void SetConstructStub(Code* code);
 
   // Returns if this function has been compiled to native code yet.
-  inline bool is_compiled();
+  inline bool is_compiled() const;
 
   // [length]: The function length - usually the number of declared parameters.
   // Use up to 2^30 parameters.