Implement tracking and optimizations of packed arrays

src/mips/builtins-mips.cc

Index: src/mips/builtins-mips.cc
diff --git a/src/mips/builtins-mips.cc b/src/mips/builtins-mips.cc
index eeb84c3a941121bc61851526d0c6e7ed0de33b2a..5a2074e6523566837917c4a97b532f9ee94623bf 100644
--- a/src/mips/builtins-mips.cc
+++ b/src/mips/builtins-mips.cc
@@ -118,7 +118,7 @@ static void AllocateEmptyJSArray(MacroAssembler* masm,
                                  Label* gc_required) {
   const int initial_capacity = JSArray::kPreallocatedArrayElements;
   STATIC_ASSERT(initial_capacity >= 0);
-  __ LoadInitialArrayMap(array_function, scratch2, scratch1);
+  __ LoadInitialArrayMap(array_function, scratch2, scratch1, false);
 
   // Allocate the JSArray object together with space for a fixed array with the
   // requested elements.
@@ -214,7 +214,8 @@ static void AllocateJSArray(MacroAssembler* masm,
                             bool fill_with_hole,
                             Label* gc_required) {
   // Load the initial map from the array function.
-  __ LoadInitialArrayMap(array_function, scratch2, elements_array_storage);
+  __ LoadInitialArrayMap(array_function, scratch2,
+                         elements_array_storage, fill_with_hole);
 
   if (FLAG_debug_code) {  // Assert that array size is not zero.
     __ Assert(
@@ -449,10 +450,10 @@ static void ArrayNativeCode(MacroAssembler* masm,
   __ Branch(call_generic_code);
 
   __ bind(&not_double);
-  // Transition FAST_SMI_ONLY_ELEMENTS to FAST_ELEMENTS.
+  // Transition FAST_SMI_ELEMENTS to FAST_ELEMENTS.
   // a3: JSArray
   __ lw(a2, FieldMemOperand(a3, HeapObject::kMapOffset));
-  __ LoadTransitionedArrayMapConditional(FAST_SMI_ONLY_ELEMENTS,
+  __ LoadTransitionedArrayMapConditional(FAST_SMI_ELEMENTS,
                                          FAST_ELEMENTS,
                                          a2,
                                          t5,