Fix KeyedAccessStoreMode on Windows

src/ast.h

Index: src/ast.h
diff --git a/src/ast.h b/src/ast.h
index dddfc835fd284d400973b7c9cd994c3627bbeac7..6d126b18921eb35c6f9be899e66ef25a77260c10 100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -1811,7 +1811,7 @@ class CountOperation: public Expression {
   Token::Value op_;
   bool is_prefix_ : 1;
   bool is_monomorphic_ : 1;
-  KeyedAccessStoreMode store_mode_: 4;
+  KeyedAccessStoreMode store_mode_: 5;

[Jakob Kummerow, 2013/04/09 16:18:20]

Let's add a comment that an extra bit is needed because the Windows compiler
interprets packed bit fields as signed integers.

   Expression* expression_;
   int pos_;
   const BailoutId assignment_id_;
@@ -1953,7 +1953,7 @@ class Assignment: public Expression {
   const BailoutId assignment_id_;
 
   bool is_monomorphic_ : 1;
-  KeyedAccessStoreMode store_mode_ : 4;
+  KeyedAccessStoreMode store_mode_ : 5;
   SmallMapList receiver_types_;
 };