Move DescriptorArray into the map

src/arm/macro-assembler-arm.cc

Index: src/arm/macro-assembler-arm.cc
diff --git a/src/arm/macro-assembler-arm.cc b/src/arm/macro-assembler-arm.cc
index 31915a5194d2c14b29ea940c859248d6342c18af..4409e2643afa32b79a7c0d309f3a4d22f1a7d4a1 100644
--- a/src/arm/macro-assembler-arm.cc
+++ b/src/arm/macro-assembler-arm.cc
@@ -3742,29 +3742,7 @@ void MacroAssembler::ClampDoubleToUint8(Register result_reg,
 void MacroAssembler::LoadInstanceDescriptors(Register map,
                                              Register descriptors,
                                              Register scratch) {
-  Register temp = descriptors;
-  ldr(temp, FieldMemOperand(map, Map::kTransitionsOrBackPointerOffset));
-
-  Label ok, fail, load_from_back_pointer;
-  CheckMap(temp,
-           scratch,
-           isolate()->factory()->fixed_array_map(),
-           &fail,
-           DONT_DO_SMI_CHECK);
-  ldr(descriptors, FieldMemOperand(temp, TransitionArray::kDescriptorsOffset));
-  jmp(&ok);
-
-  bind(&fail);
-  CompareRoot(temp, Heap::kUndefinedValueRootIndex);
-  b(ne, &load_from_back_pointer);
-  mov(descriptors, Operand(FACTORY->empty_descriptor_array()));
-  jmp(&ok);
-
-  bind(&load_from_back_pointer);
-  ldr(temp, FieldMemOperand(temp, Map::kTransitionsOrBackPointerOffset));
-  ldr(descriptors, FieldMemOperand(temp, TransitionArray::kDescriptorsOffset));
-
-  bind(&ok);
+  ldr(descriptors, FieldMemOperand(map, Map::kDescriptorsOffset));
 }