PPC/S390: Use Load Byte to fix endianess issue

src/builtins/ppc/builtins-ppc.cc

Index: src/builtins/ppc/builtins-ppc.cc
diff --git a/src/builtins/ppc/builtins-ppc.cc b/src/builtins/ppc/builtins-ppc.cc
index 4265ad6e2fd2d976dd138ef5b8a4d3e5802d9f0d..06abce4b584bfcd60a09ac3da9af6b24dae5b26e 100644
--- a/src/builtins/ppc/builtins-ppc.cc
+++ b/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);