Introduce scopes to keep track of catch blocks at compile time.

src/full-codegen.h

Index: src/full-codegen.h
diff --git a/src/full-codegen.h b/src/full-codegen.h
index 50317f067359a70dabb56c008e6caf9ea8a39b8d..9ae2380d3e478b02de04e8a6ffcfefd956173245 100644
--- a/src/full-codegen.h
+++ b/src/full-codegen.h
@@ -80,6 +80,7 @@ class FullCodeGenerator: public AstVisitor {
   explicit FullCodeGenerator(MacroAssembler* masm)
       : masm_(masm),
         info_(NULL),
+        scope_(NULL),
         nesting_stack_(NULL),
         loop_depth_(0),
         context_(NULL),
@@ -531,7 +532,7 @@ class FullCodeGenerator: public AstVisitor {
     return is_strict_mode() ? kStrictMode : kNonStrictMode;
   }
   FunctionLiteral* function() { return info_->function(); }
-  Scope* scope() { return info_->scope(); }
+  Scope* scope() { return scope_; }
 
   static Register result_register();
   static Register context_register();
@@ -751,6 +752,7 @@ class FullCodeGenerator: public AstVisitor {
 
   MacroAssembler* masm_;
   CompilationInfo* info_;
+  Scope* scope_;
   Label return_label_;
   NestedStatement* nesting_stack_;
   int loop_depth_;