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/evalfunc.c b/src/evalfunc.c
index bee58ee..a00c753 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -52,6 +52,7 @@
 static void f_assert_match(typval_T *argvars, typval_T *rettv);
 static void f_assert_notequal(typval_T *argvars, typval_T *rettv);
 static void f_assert_notmatch(typval_T *argvars, typval_T *rettv);
+static void f_assert_report(typval_T *argvars, typval_T *rettv);
 static void f_assert_true(typval_T *argvars, typval_T *rettv);
 #ifdef FEAT_FLOAT
 static void f_asin(typval_T *argvars, typval_T *rettv);
@@ -483,6 +484,7 @@
     {"assert_match",	2, 3, f_assert_match},
     {"assert_notequal",	2, 3, f_assert_notequal},
     {"assert_notmatch",	2, 3, f_assert_notmatch},
+    {"assert_report",	1, 1, f_assert_report},
     {"assert_true",	1, 2, f_assert_true},
 #ifdef FEAT_FLOAT
     {"atan",		1, 1, f_atan},
@@ -1314,6 +1316,15 @@
 }
 
 /*
+ * "assert_report(msg)" function
+ */
+    static void
+f_assert_report(typval_T *argvars, typval_T *rettv UNUSED)
+{
+    assert_report(argvars);
+}
+
+/*
  * "assert_true(actual[, msg])" function
  */
     static void