[debugger] pause stdin on debugEval

lib/_debugger.js

@@ -743,14 +743,17 @@ Interface.prototype.controlEval = function(code, context, filename, callback) {
 };
 
 Interface.prototype.debugEval = function(code, context, filename, callback) {
-  var client = this.client;
+  var self = this,
+      client = this.client;
 
   if (code === '.scope') {
     client.reqScopes(callback);
     return;
   }
 
+  self.pause();
   client.reqEval(code, function(res) {
+    self.resume();
     if (!res.success) {
       if (res.message) {
         callback(res.message);