[contexts] Place the initial JSArray maps on the native context directly.

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 e60c057f1cc823d346ff993d81e6e0dc543f6b6e..92a2419d30ae88ba45e1ff7e5c2dd45864c914b9 100644
--- a/src/mips/macro-assembler-mips.cc
+++ b/src/mips/macro-assembler-mips.cc
@@ -4703,17 +4703,17 @@ void MacroAssembler::LoadTransitionedArrayMapConditional(
     Register map_in_out,
     Register scratch,
     Label* no_map_match) {
+  DCHECK(IsFastElementsKind(expected_kind));
+  DCHECK(IsFastElementsKind(transitioned_kind));
+
   // Check that the function's map is the same as the expected cached map.
-  LoadNativeContextSlot(Context::JS_ARRAY_MAPS_INDEX, scratch);
-  size_t offset = expected_kind * kPointerSize +
-      FixedArrayBase::kHeaderSize;
-  lw(at, FieldMemOperand(scratch, offset));
+  lw(scratch, NativeContextMemOperand());
+  lw(at, ContextMemOperand(scratch, Context::ArrayMapIndex(expected_kind)));
   Branch(no_map_match, ne, map_in_out, Operand(at));
 
   // Use the transitioned cached map.
-  offset = transitioned_kind * kPointerSize +
-      FixedArrayBase::kHeaderSize;
-  lw(map_in_out, FieldMemOperand(scratch, offset));
+  lw(map_in_out,
+     ContextMemOperand(scratch, Context::ArrayMapIndex(transitioned_kind)));
 }