Squeeze the layout of expression nodes a bit.

Again 112MB less peak memory usage in the bug mentioned below. :-)
Routed all writes to to_boolean_types_ through its setter on the way.

BUG=417697
LOG=y
R=mvstanton@chromium.org

Review URL: https://codereview.chromium.org/615423006

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24393 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/ast.cc

@@ -560,7 +560,7 @@ bool FunctionDeclaration::IsInlineable() const {
 // once we use the common type field in the AST consistently.
 
 void Expression::RecordToBooleanTypeFeedback(TypeFeedbackOracle* oracle) {
-  to_boolean_types_ = oracle->ToBooleanTypes(test_id());
+  set_to_boolean_types(oracle->ToBooleanTypes(test_id()));
 }
 
 

src/ast.h

@@ -363,9 +363,12 @@ class Expression : public AstNode {
   void set_bounds(Bounds bounds) { bounds_ = bounds; }
 
   // Whether the expression is parenthesized
-  unsigned parenthesization_level() const { return parenthesization_level_; }
-  bool is_parenthesized() const { return parenthesization_level_ > 0; }
-  void increase_parenthesization_level() { ++parenthesization_level_; }
+  bool is_parenthesized() const { return is_parenthesized_; }
+  bool is_multi_parenthesized() const { return is_multi_parenthesized_; }
+  void increase_parenthesization_level() {
+    is_multi_parenthesized_ = is_parenthesized_;
+    is_parenthesized_ = true;
+  }
 
   // Type feedback information for assignments and properties.
   virtual bool IsMonomorphic() {
@@ -391,16 +394,18 @@ class Expression : public AstNode {
  protected:
   Expression(Zone* zone, int pos, IdGen* id_gen)
       : AstNode(pos),
+        is_parenthesized_(false),
+        is_multi_parenthesized_(false),
         bounds_(Bounds::Unbounded(zone)),
-        parenthesization_level_(0),
         id_(id_gen->GetNextId()),
         test_id_(id_gen->GetNextId()) {}
   void set_to_boolean_types(byte types) { to_boolean_types_ = types; }
 
  private:
-  Bounds bounds_;
   byte to_boolean_types_;
-  unsigned parenthesization_level_;
+  bool is_parenthesized_ : 1;
+  bool is_multi_parenthesized_ : 1;
+  Bounds bounds_;
 
   const BailoutId id_;
   const TypeFeedbackId test_id_;

src/parser.cc

@@ -3381,7 +3381,7 @@ bool CheckAndDeclareArrowParameter(ParserTraits* traits, Expression* expression,
 
   // Too many parentheses around expression:
   //   (( ... )) => ...
-  if (expression->parenthesization_level() > 1) return false;
+  if (expression->is_multi_parenthesized()) return false;
 
   // Case for a single parameter:
   //   (foo) => ...