MIPS: Fix packed-element.js test on ARM with no snap

src/mips/macro-assembler-mips.cc

Index: src/mips/macro-assembler-mips.cc
diff --git a/src/mips/macro-assembler-mips.cc b/src/mips/macro-assembler-mips.cc
index 51b3a3823f6082cb41c8383dafb60afc73fb80b8..1a6bc216ccc9d72c5e060249a9ec1bd42f8396eb 100644
--- a/src/mips/macro-assembler-mips.cc
+++ b/src/mips/macro-assembler-mips.cc
@@ -4459,7 +4459,8 @@ void MacroAssembler::LoadTransitionedArrayMapConditional(
                 Context::SlotOffset(Context::JS_ARRAY_MAPS_INDEX)));
   size_t offset = expected_kind * kPointerSize +
       FixedArrayBase::kHeaderSize;
-  Branch(no_map_match, ne, map_in_out, Operand(scratch));
+  lw(at, FieldMemOperand(scratch, offset));
+  Branch(no_map_match, ne, map_in_out, Operand(at));
 
   // Use the transitioned cached map.
   offset = transitioned_kind * kPointerSize +