RFC: Switch to ast ids (instead of positions) for type feedback.

src/ast.h

Index: src/ast.h
diff --git a/src/ast.h b/src/ast.h
index cdf456f67b6e5e2b66cdee56b3a9c19b50a3deed..4f5980cbc6ed3f2f16a9d9c88052faf5751a6730 100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -133,8 +133,6 @@ class AstNode: public ZoneObject {
   };
 #undef DECLARE_TYPE_ENUM
 
-  static const int kNoNumber = -1;
-
   AstNode() : id_(GetNextId()) { count_++; }
 
   virtual ~AstNode() { }
@@ -161,20 +159,20 @@ class AstNode: public ZoneObject {
 
   static int Count() { return count_; }
   static void ResetIds() { current_id_ = 0; }
-  unsigned id() const { return id_; }
+  AstId id() const { return id_; }
 
  protected:
-  static unsigned GetNextId() { return current_id_++; }
-  static unsigned ReserveIdRange(int n) {
-    unsigned tmp = current_id_;
+  static AstId GetNextId() { return current_id_++; }
+  static AstId ReserveIdRange(int n) {
+    AstId tmp = current_id_;
     current_id_ += n;
     return tmp;
   }
 
  private:
-  static unsigned current_id_;
-  static unsigned count_;
-  unsigned id_;
+  static AstId current_id_;
+  static AstId count_;
+  AstId id_;
 };
 
 
@@ -438,7 +436,7 @@ class IterationStatement: public BreakableStatement {
   void set_body(Statement* stmt) { body_ = stmt; }
 
   // Bailout support.
-  int OsrEntryId() const { return osr_entry_id_; }
+  AstId OsrEntryId() const { return osr_entry_id_; }
   virtual int ContinueId() const = 0;
 
   // Code generation
@@ -454,7 +452,7 @@ class IterationStatement: public BreakableStatement {
  private:
   Statement* body_;
   BreakTarget continue_target_;
-  int osr_entry_id_;
+  AstId osr_entry_id_;
 };
 
 
@@ -1585,7 +1583,7 @@ class Assignment: public Expression {
   }
 
   // Bailout support.
-  int compound_bailout_id() const { return compound_bailout_id_; }
+  AstId compound_bailout_id() const { return compound_bailout_id_; }
 
  private:
   Token::Value op_;
@@ -1593,7 +1591,7 @@ class Assignment: public Expression {
   Expression* value_;
   int pos_;
   BinaryOperation* binary_operation_;
-  int compound_bailout_id_;
+  AstId compound_bailout_id_;
 
   bool block_start_;
   bool block_end_;