Revert "Revert "Reland 21774: Generate KeyedLoadGeneric with Hydrogen""

src/elements-kind.cc

Index: src/elements-kind.cc
diff --git a/src/elements-kind.cc b/src/elements-kind.cc
index 845286decce583259c654a50fd18f684e437831f..cd946e8028daca7638fb30b764cd39d2b80201bf 100644
--- a/src/elements-kind.cc
+++ b/src/elements-kind.cc
@@ -53,8 +53,9 @@ int ElementsKindToShiftSize(ElementsKind elements_kind) {
 
 
 int GetDefaultHeaderSizeForElementsKind(ElementsKind elements_kind) {
+  STATIC_ASSERT(FixedArray::kHeaderSize == FixedDoubleArray::kHeaderSize);
   return IsExternalArrayElementsKind(elements_kind)
-      ? 0 : (FixedArray::kHeaderSize - kSmiTagSize);
+      ? 0 : (FixedArray::kHeaderSize - kHeapObjectTag);
 }