debugger: show current line, fix for #6150

Author: rlidwka

lib/_debugger.js

@@ -1153,7 +1153,14 @@ Interface.prototype.list = function(delta) {
         line = lines[i];
       }
 
-      self.print(leftPad(lineno, breakpoint && '*') + ' ' + line);
+      var prefixChar = ' ';
+      if (current) {
+        prefixChar = '>';
+      } else if (breakpoint) {
+        prefixChar = '*';
+      }
+
+      self.print(leftPad(lineno, prefixChar) + ' ' + line);
     }
     self.resume();
   });