Remove HFixedArrayBaseLength instruction and replace with regular HLoadNamedField.

src/code-stubs-hydrogen.cc

Index: src/code-stubs-hydrogen.cc
diff --git a/src/code-stubs-hydrogen.cc b/src/code-stubs-hydrogen.cc
index 06c9039614ce2c1c8e658d602b0ac5fb9305010f..96266af119f8821a960aed34bb0cfce1076de46f 100644
--- a/src/code-stubs-hydrogen.cc
+++ b/src/code-stubs-hydrogen.cc
@@ -510,8 +510,7 @@ HValue* CodeStubGraphBuilder<TransitionElementsKindStub>::BuildCodeStub() {
 
   HInstruction* elements = AddLoadElements(js_array);
 
-  HInstruction* elements_length =
-      AddInstruction(new(zone) HFixedArrayBaseLength(elements));
+  HInstruction* elements_length = AddLoadFixedArrayLength(elements);
 
   HValue* new_elements = BuildAllocateElementsAndInitializeElementsHeader(
       context(), to_kind, elements_length);