[es6] Fix prototype chain walk for instanceof.

src/crankshaft/mips/lithium-codegen-mips.cc

Index: src/crankshaft/mips/lithium-codegen-mips.cc
diff --git a/src/crankshaft/mips/lithium-codegen-mips.cc b/src/crankshaft/mips/lithium-codegen-mips.cc
index 490ed7a0ac58ced7fb6f95fd9f4deabd7a73236b..4c2b1580dda135341c7b6dbc3904c750d80474a6 100644
--- a/src/crankshaft/mips/lithium-codegen-mips.cc
+++ b/src/crankshaft/mips/lithium-codegen-mips.cc
@@ -2417,9 +2417,9 @@ void LCodeGen::DoHasInPrototypeChainAndBranch(
                Operand(JS_PROXY_TYPE));
 
   __ lw(object_prototype, FieldMemOperand(object_map, Map::kPrototypeOffset));
-  EmitTrueBranch(instr, eq, object_prototype, Operand(prototype));
   __ LoadRoot(at, Heap::kNullValueRootIndex);
   EmitFalseBranch(instr, eq, object_prototype, Operand(at));
+  EmitTrueBranch(instr, eq, object_prototype, Operand(prototype));
   __ Branch(USE_DELAY_SLOT, &loop);
   __ lw(object_map, FieldMemOperand(object_prototype, HeapObject::kMapOffset));
 }