unictype/category-byname tests: Fix gcc -Wunused-value warning

[Bruno Haible]

This patch fixes the warning

unictype/test-categ_byname.c:209:3: warning: statement with no effect 
[-Wunused-value]


2023-09-04  Bruno Haible  <br...@clisp.org>

        unictype/category-byname tests: Fix gcc -Wunused-value warning.
        * tests/unictype/test-categ_byname.c (main): Add some tests for category
        Nl.

diff --git a/tests/unictype/test-categ_byname.c 
b/tests/unictype/test-categ_byname.c
index 2489caaa28..5c9df4f1d0 100644
--- a/tests/unictype/test-categ_byname.c
+++ b/tests/unictype/test-categ_byname.c
@@ -206,8 +206,6 @@ main ()
   ASSERT (category_equals (uc_general_category_byname ("UNASSIGNED"), 
UC_CATEGORY_Cn));
   ASSERT (category_equals (uc_general_category_byname ("Unassigned"), 
UC_CATEGORY_Cn));
 
-  uc_general_category_byname ("Nl");
-
   {
     uc_general_category_t ct = uc_general_category_byname ("Nd");
     unsigned int c;
@@ -218,6 +216,16 @@ main ()
       ASSERT (!uc_is_general_category (c, ct));
   }
 
+  {
+    uc_general_category_t ct = uc_general_category_byname ("Nl");
+    unsigned int c;
+
+    for (c = 0x2160; c < 0x2180; c++)
+      ASSERT (uc_is_general_category (c, ct));
+    ASSERT (!uc_is_general_category (0x0BF1, ct));
+    ASSERT (!uc_is_general_category (0x0D71, ct));
+  }
+
   {
     uc_general_category_t ct = uc_general_category_byname ("Foo");
     unsigned int c;