Implement Function.prototype.toMethod.

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index fd08c8292f812c8c3084fb699eb9f65dcc98b4a7..6881be085e73df5d23a7055e27302663d0cbc537 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -2877,6 +2877,7 @@ void Heap::CreateInitialObjects() {
   set_observed_symbol(*factory->NewPrivateSymbol());
   set_stack_trace_symbol(*factory->NewPrivateSymbol());
   set_uninitialized_symbol(*factory->NewPrivateSymbol());
+  set_home_object_symbol(*factory->NewPrivateOwnSymbol());
 
   Handle<SeededNumberDictionary> slow_element_dictionary =
       SeededNumberDictionary::New(isolate(), 0, TENURED);
@@ -3679,10 +3680,6 @@ 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());
-
   // Make the clone.
   Map* map = source->map();
   int object_size = map->instance_size();
@@ -3756,6 +3753,29 @@ AllocationResult Heap::CopyJSObject(JSObject* source, AllocationSite* site) {
     }
     JSObject::cast(clone)->set_properties(prop, wb_mode);
   }
+
+  // Clean up literals array.
+  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;
 }