patch 8.2.2922: computing array length is done in various ways

Problem:    Computing array length is done in various ways.
Solution:   Use ARRAY_LENGTH everywhere. (Ken Takata, closes #8305)
diff --git a/src/evalfunc.c b/src/evalfunc.c
index 16447ab..fcb64f6 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -1877,7 +1877,7 @@
 	    return name;
 	}
     }
-    if (++intidx < (int)(sizeof(global_functions) / sizeof(funcentry_T)))
+    if (++intidx < (int)ARRAY_LENGTH(global_functions))
     {
 	STRCPY(IObuff, global_functions[intidx].f_name);
 	STRCAT(IObuff, "(");
@@ -1923,7 +1923,7 @@
     int		cmp;
     int		x;
 
-    last = (int)(sizeof(global_functions) / sizeof(funcentry_T)) - 1;
+    last = (int)ARRAY_LENGTH(global_functions) - 1;
 
     // Find the function name in the table. Binary search.
     while (first <= last)