patch 8.0.0477: the client-server test may hang when failing

Problem:    The client-server test may hang when failing.
Solution:   Set a timer.  Add assert_report()
diff --git a/src/eval.c b/src/eval.c
index 56bb21f..e588c23 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -9084,6 +9084,17 @@
 }
 
     void
+assert_report(typval_T *argvars)
+{
+    garray_T	ga;
+
+    prepare_assert_error(&ga);
+    ga_concat(&ga, get_tv_string(&argvars[0]));
+    assert_error(&ga);
+    ga_clear(&ga);
+}
+
+    void
 assert_exception(typval_T *argvars)
 {
     garray_T	ga;