Fix keyed element access wrt string wrappers

src/mips/macro-assembler-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <limits.h>  // For LONG_MIN, LONG_MAX.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_MIPS
 
@@ skipping 5967 matching lines @@
 
 
 void MacroAssembler::JumpIfDictionaryInPrototypeChain(
     Register object,
     Register scratch0,
     Register scratch1,
     Label* found) {
   DCHECK(!scratch1.is(scratch0));
   Factory* factory = isolate()->factory();
   Register current = scratch0;
-  Label loop_again;
+  Label loop_again, end;
 
   // Scratch contained elements pointer.
   Move(current, object);
+  lw(current, FieldMemOperand(current, HeapObject::kMapOffset));
+  lw(current, FieldMemOperand(current, Map::kPrototypeOffset));
+  Branch(&end, eq, current, Operand(factory->null_value()));
 
   // Loop based on the map going up the prototype chain.
   bind(&loop_again);
   lw(current, FieldMemOperand(current, HeapObject::kMapOffset));
+  lbu(scratch1, FieldMemOperand(current, Map::kInstanceTypeOffset));
+  STATIC_ASSERT(JS_VALUE_TYPE < JS_OBJECT_TYPE);
+  STATIC_ASSERT(JS_PROXY_TYPE < JS_OBJECT_TYPE);
+  Branch(found, lo, scratch1, Operand(JS_OBJECT_TYPE));
   lb(scratch1, FieldMemOperand(current, Map::kBitField2Offset));
   DecodeField<Map::ElementsKindBits>(scratch1);
   Branch(found, eq, scratch1, Operand(DICTIONARY_ELEMENTS));
   lw(current, FieldMemOperand(current, Map::kPrototypeOffset));
   Branch(&loop_again, ne, current, Operand(factory->null_value()));
+
+  bind(&end);
 }
 
 
 bool AreAliased(Register reg1,
                 Register reg2,
                 Register reg3,
                 Register reg4,
                 Register reg5,
                 Register reg6,
                 Register reg7,
@@ skipping 95 matching lines @@
   if (mag.shift > 0) sra(result, result, mag.shift);
   srl(at, dividend, 31);
   Addu(result, result, Operand(at));
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS