[WIP] JSForInLowering and JSForInHasOwnProperty.

src/compiler/typer.cc

 // Copyright 2014 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 "src/compiler/typer.h"
 
 #include <iomanip>
 
 #include "src/base/flags.h"
 #include "src/bootstrapper.h"
@@ skipping 1633 matching lines @@
   // have a few weird runtime calls that return the hole or even FixedArrays;
   // change this once those weird runtime calls have been removed.
   return Type::Any();
 }
 
 
 Type* Typer::Visitor::TypeJSConvertReceiver(Node* node) {
   return Type::Receiver();
 }
 
+Type* Typer::Visitor::TypeJSForInHasOwnProperty(Node* node) {
+  return Type::Boolean();
+}
+
+Type* Typer::Visitor::TypeJSForInLoadProperty(Node* node) {
+  return Type::NonInternal();
+}
 
 Type* Typer::Visitor::TypeJSForInNext(Node* node) {
-  return Type::Union(Type::String(), Type::Undefined(), zone());
+  return Type::StringOrUndefined();
 }
 
 
 Type* Typer::Visitor::TypeJSForInPrepare(Node* node) {
   STATIC_ASSERT(Map::EnumLengthBits::kMax <= FixedArray::kMaxLength);
   Type* const cache_type =
       Type::Union(Type::SignedSmall(), Type::OtherInternal(), zone());
   Type* const cache_array = Type::OtherInternal();
   Type* const cache_length = typer_->cache_.kFixedArrayLengthType;
   return Type::Tuple(cache_type, cache_array, cache_length, zone());
@@ skipping 204 matching lines @@
   if (type->Maybe(Type::Hole())) {
     // Turn "the hole" into undefined.
     type = Type::Intersect(type, Type::NonInternal(), zone());
     type = Type::Union(type, Type::Undefined(), zone());
   }
   return type;
 }
 
 Type* Typer::Visitor::TypeAllocate(Node* node) { return Type::Any(); }
 
+Type* Typer::Visitor::TypeLoadFieldByIndex(Node* node) {
+  return Type::NonInternal();
+}
+
 Type* Typer::Visitor::TypeLoadField(Node* node) {
   return FieldAccessOf(node->op()).type;
 }
 
 Type* Typer::Visitor::TypeLoadBuffer(Node* node) {
   switch (BufferAccessOf(node->op()).external_array_type()) {
 #define TYPED_ARRAY_CASE(ElemType, type, TYPE, ctype, size) \
   case kExternal##ElemType##Array:                          \
     return Type::Union(typer_->cache_.k##ElemType, Type::Undefined(), zone());
     TYPED_ARRAYS(TYPED_ARRAY_CASE)
@@ skipping 101 matching lines @@
 Type* Typer::Visitor::TypeConstant(Handle<Object> value) {
   if (Type::IsInteger(*value)) {
     return Type::Range(value->Number(), value->Number(), zone());
   }
   return Type::NewConstant(value, zone());
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8