[debugger] Ensure at least one breakable position per function.

src/full-codegen/full-codegen.h

Index: src/full-codegen/full-codegen.h
diff --git a/src/full-codegen/full-codegen.h b/src/full-codegen/full-codegen.h
index e811e25cf818abb9f9816fc3a9b3321394aa91ce..647f6ad8104f45298c03cdf0a8873dae1c418acf 100644
--- a/src/full-codegen/full-codegen.h
+++ b/src/full-codegen/full-codegen.h
@@ -684,6 +684,8 @@ class FullCodeGenerator: public AstVisitor {
   void EmitContinue(Statement* target);
   void EmitBreak(Statement* target);
 
+  void EmitIllegalRedeclaration();
+
   // Loop nesting counter.
   int loop_depth() { return loop_depth_; }
   void increment_loop_depth() { loop_depth_++; }