[turbofan] First steps towards optimizing for-in loops.

src/compiler/access-builder.cc

Index: src/compiler/access-builder.cc
diff --git a/src/compiler/access-builder.cc b/src/compiler/access-builder.cc
index fa27c1563680d63018a78c2479068729696e31c0..c728154d7f4e2bb263f6bdf3d9fc64ae55f97bfe 100644
--- a/src/compiler/access-builder.cc
+++ b/src/compiler/access-builder.cc
@@ -59,6 +59,34 @@ FieldAccess AccessBuilder::ForExternalArrayPointer() {
 
 
 // static
+FieldAccess AccessBuilder::ForDescriptorArrayEnumCache() {
+  return {kTaggedBase, DescriptorArray::kEnumCacheOffset, Handle<Name>(),
+          Type::TaggedPointer(), kMachAnyTagged};
+}
+
+
+// static
+FieldAccess AccessBuilder::ForDescriptorArrayEnumCacheBridgeCache() {
+  return {kTaggedBase, DescriptorArray::kEnumCacheBridgeCacheOffset,
+          Handle<Name>(), Type::TaggedPointer(), kMachAnyTagged};
+}
+
+
+// static
+FieldAccess AccessBuilder::ForMapBitField3() {
+  return {kTaggedBase, Map::kBitField3Offset, Handle<Name>(),
+          Type::UntaggedUnsigned32(), kMachUint32};
+}
+
+
+// static
+FieldAccess AccessBuilder::ForMapDescriptors() {
+  return {kTaggedBase, Map::kDescriptorsOffset, Handle<Name>(),
+          Type::TaggedPointer(), kMachAnyTagged};
+}
+
+
+// static
 FieldAccess AccessBuilder::ForMapInstanceType() {
   return {kTaggedBase, Map::kInstanceTypeOffset, Handle<Name>(),
           Type::UntaggedUnsigned8(), kMachUint8};