FYI Implementing 'super' keyword

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index a4a970534e34e85133d672e0c2c9a412f06c4702..ae5613eaf76ede98e18740c130695266f574f55f 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -3589,7 +3589,7 @@ AllocationResult Heap::AllocateJSObject(JSFunction* constructor,
 AllocationResult Heap::CopyJSObject(JSObject* source, AllocationSite* site) {
   // Never used to copy functions.  If functions need to be copied we
   // have to be careful to clear the literals array.
-  SLOW_DCHECK(!source->IsJSFunction());
+  // SLOW_DCHECK(!source->IsJSFunction());
 
   // Make the clone.
   Map* map = source->map();
@@ -3664,6 +3664,28 @@ AllocationResult Heap::CopyJSObject(JSObject* source, AllocationSite* site) {
     }
     JSObject::cast(clone)->set_properties(prop, wb_mode);
   }
+
+  if (source->IsJSFunction()) {
+    SLOW_DCHECK(clone->IsJSFunction());
+    JSFunction* source_fun = JSFunction::cast(source);
+    JSFunction* clone_fun = JSFunction::cast(clone);
+    SharedFunctionInfo* info = source_fun->shared();
+    if (!info->bound()) {
+      int num_literals = info->num_literals();
+      HeapObject* obj;
+      {
+        AllocationResult allocation = AllocateFixedArrayWithFiller(
+            num_literals, NOT_TENURED, undefined_value());
+        if (!allocation.To(&obj)) return allocation;
+      }
+      FixedArray* new_literals = FixedArray::cast(obj);
+      if (num_literals > 0) {
+        new_literals->set(JSFunction::kLiteralNativeContextIndex,
+            JSFunction::NativeContextFromLiterals(source_fun->literals()));
+      }
+      clone_fun->set_literals(new_literals);
+    }
+  }
   // Return the new clone.
   return clone;
 }