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

src/ppc/macro-assembler-ppc.cc

Index: src/ppc/macro-assembler-ppc.cc
diff --git a/src/ppc/macro-assembler-ppc.cc b/src/ppc/macro-assembler-ppc.cc
index 904072897cfeda499460f4631ae603c32e7fa1e9..0b9459fb2d44358f1c279751f7e03c5f316860d6 100644
--- a/src/ppc/macro-assembler-ppc.cc
+++ b/src/ppc/macro-assembler-ppc.cc
@@ -2470,16 +2470,18 @@ void MacroAssembler::LoadContext(Register dst, int context_chain_length) {
 void MacroAssembler::LoadTransitionedArrayMapConditional(
     ElementsKind expected_kind, ElementsKind transitioned_kind,
     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;
-  LoadP(ip, FieldMemOperand(scratch, offset));
+  LoadP(scratch, NativeContextMemOperand());
+  LoadP(ip, ContextMemOperand(scratch, Context::ArrayMapIndex(expected_kind)));
   cmp(map_in_out, ip);
   bne(no_map_match);
 
   // Use the transitioned cached map.
-  offset = transitioned_kind * kPointerSize + FixedArrayBase::kHeaderSize;
-  LoadP(map_in_out, FieldMemOperand(scratch, offset));
+  LoadP(map_in_out,
+        ContextMemOperand(scratch, Context::ArrayMapIndex(transitioned_kind)));
 }