Fix keyed element access wrt string wrappers

src/ia32/macro-assembler-ia32.cc

Index: src/ia32/macro-assembler-ia32.cc
diff --git a/src/ia32/macro-assembler-ia32.cc b/src/ia32/macro-assembler-ia32.cc
index 42a151e27afa2c7205600f290328c6cc2748ec80..16b47d10cd862cd5744d86605c2c3bb3ec781b40 100644
--- a/src/ia32/macro-assembler-ia32.cc
+++ b/src/ia32/macro-assembler-ia32.cc
@@ -3178,14 +3178,22 @@ void MacroAssembler::JumpIfDictionaryInPrototypeChain(
   DCHECK(!scratch1.is(scratch0));
   Factory* factory = isolate()->factory();
   Register current = scratch0;
-  Label loop_again;
+  Label loop_again, end;
 
   // scratch contained elements pointer.
   mov(current, object);
+  mov(current, FieldOperand(current, HeapObject::kMapOffset));
+  mov(current, FieldOperand(current, Map::kPrototypeOffset));
+  cmp(current, Immediate(factory->null_value()));
+  j(equal, &end);
 
   // Loop based on the map going up the prototype chain.
   bind(&loop_again);
   mov(current, FieldOperand(current, HeapObject::kMapOffset));
+  STATIC_ASSERT(JS_PROXY_TYPE < JS_OBJECT_TYPE);
+  STATIC_ASSERT(JS_VALUE_TYPE < JS_OBJECT_TYPE);
+  CmpInstanceType(current, JS_OBJECT_TYPE);
+  j(below, found);
   mov(scratch1, FieldOperand(current, Map::kBitField2Offset));
   DecodeField<Map::ElementsKindBits>(scratch1);
   cmp(scratch1, Immediate(DICTIONARY_ELEMENTS));
@@ -3193,6 +3201,8 @@ void MacroAssembler::JumpIfDictionaryInPrototypeChain(
   mov(current, FieldOperand(current, Map::kPrototypeOffset));
   cmp(current, Immediate(factory->null_value()));
   j(not_equal, &loop_again);
+
+  bind(&end);
 }