Port FastCloneShallowArrayStub to Turbofan

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 d34f58c4854681062a2afb882b9eaaf3590182b7..8a0fe27bb7360d20436573cb31bbf0c2660d0a70 100644
--- a/src/code-stub-assembler.h
+++ b/src/code-stub-assembler.h
@@ -72,6 +72,8 @@ class CodeStubAssembler : public compiler::CodeAssembler {
 
   compiler::Node* BooleanMapConstant();
   compiler::Node* EmptyStringConstant();
+  compiler::Node* FixedArrayMapConstant();
+  compiler::Node* FixedCowArrayMapConstant();
   compiler::Node* HeapNumberMapConstant();
   compiler::Node* NoContextConstant();
   compiler::Node* NanConstant();
@@ -210,6 +212,8 @@ class CodeStubAssembler : public compiler::CodeAssembler {
   compiler::Node* LoadProperties(compiler::Node* object);
   // Load the elements backing store of a JSObject.
   compiler::Node* LoadElements(compiler::Node* object);
+  // Load the length of a JSArray instance.
+  compiler::Node* LoadJSArrayLength(compiler::Node* array);
   // Load the length of a fixed array base instance.
   compiler::Node* LoadFixedArrayBaseLength(compiler::Node* array);
   // Load the length of a fixed array base instance.
@@ -317,12 +321,18 @@ class CodeStubAssembler : public compiler::CodeAssembler {
   compiler::Node* AllocateSeqTwoByteString(int length);
   compiler::Node* AllocateSeqTwoByteString(compiler::Node* context,
                                            compiler::Node* length);
-  // Allocated an JSArray
-  compiler::Node* AllocateJSArray(ElementsKind kind, compiler::Node* array_map,
-                                  compiler::Node* capacity,
-                                  compiler::Node* length,
-                                  compiler::Node* allocation_site = nullptr,
-                                  ParameterMode mode = INTEGER_PARAMETERS);
+  // Allocate a JSArray and its elements if capacity is not null.
+  // Also initializes JSArray header fields.
+  compiler::Node* AllocateEmptyJSArray(
+      ElementsKind kind, compiler::Node* array_map, compiler::Node* length,
+      compiler::Node* allocation_site = nullptr,
+      ParameterMode mode = INTEGER_PARAMETERS,
+      compiler::Node* capacity = nullptr);
+  // Allocate a JSArray and fill elements with zero.
+  compiler::Node* AllocateFilledJSArray(
+      ElementsKind kind, compiler::Node* array_map, compiler::Node* capacity,
+      compiler::Node* length, compiler::Node* allocation_site = nullptr,
+      ParameterMode mode = INTEGER_PARAMETERS);
 
   compiler::Node* AllocateFixedArray(ElementsKind kind,
                                      compiler::Node* capacity,