Implement structural function and array types

src/hydrogen.h

Index: src/hydrogen.h
diff --git a/src/hydrogen.h b/src/hydrogen.h
index 6d81307e2cb293e1f3678693998cdda3565b64a4..b877696ae6ae63a64f3c2cf97cf81ef1cabe6e1d 100644
--- a/src/hydrogen.h
+++ b/src/hydrogen.h
@@ -2378,7 +2378,7 @@ class HOptimizedGraphBuilder : public HGraphBuilder, public AstVisitor {
         context = context->native_context();
         return handle(context->string_function()->initial_map());
       } else {
-        return type_->AsClass();
+        return type_->AsClass()->Map();
       }
     }
     Type* type() const { return type_; }