Don't build dart2js_bot on debug dart2js bots

dart.gyp

Index: dart.gyp
===================================================================
--- dart.gyp	(revision 35843)
+++ dart.gyp	(working copy)
@@ -104,6 +104,19 @@
       ],
     },
     {
+      # This is the target that is built on the dart2js debug build bots.
+      # It must depend on anything that is required by the dart2js
+      # test suites.
+      # We have this additional target because the try target takes to long
+      # to build in debug mode and will make the build step time out.
+      'target_name': 'dart2js_bot_debug',
+      'type': 'none',
+      'dependencies': [
+        'create_sdk',
+        'packages',
+      ],
+    },
+    {
       'target_name': 'api_docs',
       'type': 'none',
       'dependencies': [