[test] lit.cfg: List the contents of the remote directory after upload

This will be very helpful while debugging CI issues.

Author: lorentey

test/lit.cfg

@@ -1886,6 +1886,18 @@ def configure_remote_run():
                      os.path.dirname(local_swift_reflection_test),
                      'bin/')
 
+        print("Contents of {0} on {1} after upload:".format(
+            remote_lib_dir, remote_run_host))
+        subprocess.check_call(
+            [
+                os.path.join(config.swift_utils, 'remote-run'),
+                '--remote-dir', remote_tmp_dir,
+            ] + remote_run_extra_args + [
+                remote_run_host,
+                '--',
+                'ls', '-l', remote_lib_dir
+            ])
+
     config.target_env_prefix = 'REMOTE_RUN_CHILD_'
     config.target_run = (
         "/usr/bin/env " +