More refactoring of class Compiler's interface.

src/ast.h

Index: src/ast.h
diff --git a/src/ast.h b/src/ast.h
index fc34fd4614b4e3cd4512dc9a0be79e30dab21d59..e8d54e46898de2bcb27a5b842b8916829aaf17bf 100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -1436,6 +1436,11 @@ class FunctionLiteral: public Expression {
 
   bool AllowsLazyCompilation();
 
+  Handle<String> debug_name() const {
+    if (name_->length() > 0) return name_;
+    return inferred_name();
+  }
+
   Handle<String> inferred_name() const { return inferred_name_; }
   void set_inferred_name(Handle<String> inferred_name) {
     inferred_name_ = inferred_name;