De-virtualize AstString.

src/ast/ast-value-factory.cc

Index: src/ast/ast-value-factory.cc
diff --git a/src/ast/ast-value-factory.cc b/src/ast/ast-value-factory.cc
index 63b40d2286a82cbe1ff7a939eaf89b731c3870ff..52b2050749f73b4d9b03503f4fb91452cf59f68c 100644
--- a/src/ast/ast-value-factory.cc
+++ b/src/ast/ast-value-factory.cc
@@ -82,6 +82,19 @@ class AstRawStringInternalizationKey : public HashTableKey {
   const AstRawString* string_;
 };
 
+int AstString::length() const {
+  if (is_raw_) {
+    return reinterpret_cast<const AstRawString*>(this)->length();
+  }
+  return reinterpret_cast<const AstConsString*>(this)->length();
+}
+
+void AstString::Internalize(Isolate* isolate) {
+  if (is_raw_) {
+    return reinterpret_cast<AstRawString*>(this)->Internalize(isolate);
+  }
+  return reinterpret_cast<AstConsString*>(this)->Internalize(isolate);
+}
 
 void AstRawString::Internalize(Isolate* isolate) {
   if (!string_.is_null()) return;