Move function length tracking from Scope to (Pre)?ParserFormalParameters.

src/parsing/parser.h

 // Copyright 2012 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.
 
 #ifndef V8_PARSING_PARSER_H_
 #define V8_PARSING_PARSER_H_
 
 #include "src/ast/ast.h"
 #include "src/ast/scopes.h"
 #include "src/parsing/parser-base.h"
@@ skipping 116 matching lines @@
     bool is_rest;
     bool is_simple() const {
       return pattern->IsVariableProxy() && initializer == nullptr && !is_rest;
     }
   };
 
   explicit ParserFormalParameters(DeclarationScope* scope)
       : FormalParametersBase(scope), params(4, scope->zone()) {}
   ZoneList<Parameter> params;
 
-  int Arity() const { return params.length(); }
   const Parameter& at(int i) const { return params[i]; }
 };
 
 template <>
 struct ParserTypes<Parser> {
   typedef ParserBase<Parser> Base;
   typedef Parser Impl;
 
   typedef v8::internal::Variable Variable;
 
@@ skipping 839 matching lines @@
       if (!*ok) return;
     }
     if (init_block != nullptr) body->Add(init_block, zone());
   }
 
   V8_INLINE void AddFormalParameter(ParserFormalParameters* parameters,
                                     Expression* pattern,
                                     Expression* initializer,
                                     int initializer_end_position,
                                     bool is_rest) {
+    parameters->UpdateArityAndFunctionLength(initializer != nullptr, is_rest);
     bool is_simple = pattern->IsVariableProxy() && initializer == nullptr;
     const AstRawString* name = is_simple
                                    ? pattern->AsVariableProxy()->raw_name()
                                    : ast_value_factory()->empty_string();
     parameters->params.Add(
         ParserFormalParameters::Parameter(name, pattern, initializer,
                                           initializer_end_position, is_rest),
         parameters->scope->zone());
   }
 
@@ skipping 85 matching lines @@
   int total_preparse_skipped_;
   HistogramTimer* pre_parse_timer_;
 
   bool parsing_on_main_thread_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PARSING_PARSER_H_