[builtins] Improve performance of array.prototype.filter and map

src/code-stub-assembler.h

Index: src/code-stub-assembler.h
diff --git a/src/code-stub-assembler.h b/src/code-stub-assembler.h
index 77ec08d650f34f5e83f3d3cc448052fd3a471a06..124a0aa7ad221be24690910a4bf038803766559a 100644
--- a/src/code-stub-assembler.h
+++ b/src/code-stub-assembler.h
@@ -498,9 +498,21 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
       Node* object, Node* index, Node* value,
       ParameterMode parameter_mode = INTPTR_PARAMETERS);
 
-  Node* BuildAppendJSArray(ElementsKind kind, Node* context, Node* array,
+  // EnsureArrayPushable verifies that receiver is:
+  //   1. Is not a prototype.
+  //   2. Is not a dictionary.
+  //   3. Has a writeable length property.
+  // It returns ElementsKind as a node for further division into cases.
+  Node* EnsureArrayPushable(Node* receiver, Label* bailout);
+
+  void TryStoreArrayElement(ElementsKind kind, ParameterMode mode,
+                            Label* bailout, Node* elements, Node* index,
+                            Node* value);
+  Node* BuildAppendJSArray(ElementsKind kind, Node* array,
                            CodeStubArguments& args, Variable& arg_index,
                            Label* bailout);
+  Node* BuildAppendJSArray(ElementsKind kind, Node* array, Node* value,
+                           Label* bailout);
 
   void StoreFieldsNoWriteBarrier(Node* start_address, Node* end_address,
                                  Node* value);
@@ -660,6 +672,14 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
                              Node* capacity, Node* new_capacity,
                              ParameterMode mode, Label* bailout);
 
+  // Given a need to grow by |growth|, allocate an appropriate new capacity
+  // and return a new elements FixedArray object. Label |bailout| is
+  // followed for allocation failure. Label |fits| is followed if current
+  // capacity is sufficient.
+  Node* PossiblyGrowElementsCapacity(ParameterMode mode, ElementsKind kind,
+                                     Node* array, Node* length, Node* elements,
+                                     Node* growth, Label* fits, Label* bailout);
+
   // Allocation site manipulation
   void InitializeAllocationMemento(Node* base_allocation,
                                    int base_allocation_size,
@@ -738,6 +758,8 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   // ElementsKind helpers:
   Node* IsFastElementsKind(Node* elements_kind);
   Node* IsHoleyFastElementsKind(Node* elements_kind);
+  Node* IsElementsKindGreaterThan(Node* target_kind,
+                                  ElementsKind reference_kind);
 
   // String helpers.
   // Load a character from a String (might flatten a ConsString).