Use a filter instead of a visitor to deoptimize selected functions in a context.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index aa9b0aea2680fb35df0047051ff723c30da179f9..7a7f5f89b9e82bdf18dc73b19c23c400cde1dcd5 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -4308,13 +4308,18 @@ class Code: public HeapObject {
   // [deoptimization_data]: Array containing data for deopt.
   DECL_ACCESSORS(deoptimization_data, FixedArray)
 
-  // [type_feedback_info]: Struct containing type feedback information.
+  // [type_feedback_info]: Struct containing type feedback information for
+  // unoptimized code. Optimized code can temporarily store the head of
+  // the list of the dependent optimized functions during deoptimization.
   // STUBs can use this slot to store arbitrary information as a Smi.
-  // Will contain either a TypeFeedbackInfo object, or undefined, or a Smi.
+  // Will contain either a TypeFeedbackInfo object, or JSFunction object,
+  // or undefined, or a Smi.
   DECL_ACCESSORS(type_feedback_info, Object)
   inline void InitializeTypeFeedbackInfoNoWriteBarrier(Object* value);
   inline int stub_info();
   inline void set_stub_info(int info);
+  inline Object* deoptimizing_functions();
+  inline void set_deoptimizing_functions(Object* value);
 
   // [gc_metadata]: Field used to hold GC related metadata. The contents of this
   // field does not have to be traced during garbage collection since
@@ -5184,8 +5189,7 @@ class Map: public HeapObject {
       kConstructorOffset + kPointerSize;
   static const int kDescriptorsOffset =
       kTransitionsOrBackPointerOffset + kPointerSize;
-  static const int kCodeCacheOffset =
-      kDescriptorsOffset + kPointerSize;
+  static const int kCodeCacheOffset = kDescriptorsOffset + kPointerSize;
   static const int kBitField3Offset = kCodeCacheOffset + kPointerSize;
   static const int kSize = kBitField3Offset + kPointerSize;
 
@@ -6226,6 +6230,18 @@ class JSFunction: public JSObject {
   // Retrieve the native context from a function's literal array.
   static Context* NativeContextFromLiterals(FixedArray* literals);
 
+#ifdef DEBUG
+  bool FunctionsInFunctionListShareSameCode() {
+    Object* current = this;
+    while (!current->IsUndefined()) {
+      JSFunction* function = JSFunction::cast(current);
+      current = function->next_function_link();
+      if (function->code() != this->code()) return false;
+    }
+    return true;
+  }
+#endif
+
   // Layout descriptors. The last property (from kNonWeakFieldsEndOffset to
   // kSize) is weak and has special handling during garbage collection.
   static const int kCodeEntryOffset = JSObject::kHeaderSize;