Reland r20974: Unify and simplify the FastCloneShallowArrayStub

src/hydrogen.h

Index: src/hydrogen.h
diff --git a/src/hydrogen.h b/src/hydrogen.h
index 060ccb9b364ba880704fabdcc6fc2c4ba1fced87..42a63fd57e7e84e31142e0246d8d5a81412a98d0 100644
--- a/src/hydrogen.h
+++ b/src/hydrogen.h
@@ -1397,7 +1397,8 @@ class HGraphBuilder {
     store_map->SkipWriteBarrier();
     return store_map;
   }
-  HLoadNamedField* AddLoadElements(HValue* object);
+  HLoadNamedField* AddLoadElements(HValue* object,
+                                   HValue* dependency = NULL);
 
   bool MatchRotateRight(HValue* left,
                         HValue* right,
@@ -1413,7 +1414,12 @@ class HGraphBuilder {
                                Maybe<int> fixed_right_arg,
                                HAllocationMode allocation_mode);
 
-  HLoadNamedField* AddLoadFixedArrayLength(HValue *object);
+  HLoadNamedField* AddLoadFixedArrayLength(HValue *object,
+                                           HValue *dependency = NULL);
+
+  HLoadNamedField* AddLoadArrayLength(HValue *object,
+                                      ElementsKind kind,
+                                      HValue *dependency = NULL);
 
   HValue* AddLoadJSBuiltin(Builtins::JavaScript builtin);
 
@@ -1753,18 +1759,33 @@ class HGraphBuilder {
                                  HValue* from,
                                  HValue* to);
 
-  void BuildCopyElements(HValue* from_elements,
+  void BuildCopyElements(HValue* array,
+                         HValue* from_elements,
                          ElementsKind from_elements_kind,
                          HValue* to_elements,
                          ElementsKind to_elements_kind,
                          HValue* length,
                          HValue* capacity);
 
-  HValue* BuildCloneShallowArray(HValue* boilerplate,
-                                 HValue* allocation_site,
-                                 AllocationSiteMode mode,
-                                 ElementsKind kind,
-                                 int length);
+  HValue* BuildCloneShallowArrayCommon(HValue* boilerplate,
+                                       HValue* allocation_site,
+                                       HValue* extra_size,
+                                       HValue** return_elements,
+                                       AllocationSiteMode mode);
+
+  HValue* BuildCloneShallowArrayCow(HValue* boilerplate,
+                                    HValue* allocation_site,
+                                    AllocationSiteMode mode,
+                                    ElementsKind kind);
+
+  HValue* BuildCloneShallowArrayEmpty(HValue* boilerplate,
+                                      HValue* allocation_site,
+                                      AllocationSiteMode mode);
+
+  HValue* BuildCloneShallowArrayNonEmpty(HValue* boilerplate,
+                                         HValue* allocation_site,
+                                         AllocationSiteMode mode,
+                                         ElementsKind kind);
 
   HValue* BuildElementIndexHash(HValue* index);