PPC/S390: Use Load Byte to fix endianess issue

R=joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=
LOG=N

Review-Url: https://codereview.chromium.org/2668303002
Cr-Commit-Position: refs/heads/master@{#42864}

src/builtins/ppc/builtins-ppc.cc

@@ -2810,7 +2810,7 @@ static void CheckSpreadAndPushToStack(MacroAssembler* masm) {
   // For FastPacked kinds, iteration will have the same effect as simply
   // accessing each property in order.
   Label no_protector_check;
-  __ LoadP(scratch, FieldMemOperand(spread_map, Map::kBitField2Offset));
+  __ lbz(scratch, FieldMemOperand(spread_map, Map::kBitField2Offset));
   __ DecodeField<Map::ElementsKindBits>(scratch);
   __ cmpi(scratch, Operand(FAST_HOLEY_ELEMENTS));
   __ bgt(&runtime_call);

src/builtins/s390/builtins-s390.cc

@@ -2822,7 +2822,7 @@ static void CheckSpreadAndPushToStack(MacroAssembler* masm) {
   // For FastPacked kinds, iteration will have the same effect as simply
   // accessing each property in order.
   Label no_protector_check;
-  __ LoadP(scratch, FieldMemOperand(spread_map, Map::kBitField2Offset));
+  __ LoadlB(scratch, FieldMemOperand(spread_map, Map::kBitField2Offset));
   __ DecodeField<Map::ElementsKindBits>(scratch);
   __ CmpP(scratch, Operand(FAST_HOLEY_ELEMENTS));
   __ bgt(&runtime_call);