patch 8.2.1880: Vim9: asan complains about adding zero to NULL

Problem:    Vim9: Asan complains about adding zero to NULL.
Solution:   Check for argument count first.
diff --git a/src/version.c b/src/version.c
index a49bdd3..df85161 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1880,
+/**/
     1879,
 /**/
     1878,
diff --git a/src/vim9compile.c b/src/vim9compile.c
index 8ef1f08..934b4d6 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -1475,11 +1475,13 @@
 	isn->isn_arg.shuffle.shfl_up = argoff - 1;
     }
 
-    // Check the types of the arguments.
-    argtypes = ((type_T **)stack->ga_data) + stack->ga_len - argcount;
-    if (argcount > 0 && internal_func_check_arg_types(
-					argtypes, func_idx, argcount) == FAIL)
+    if (argcount > 0)
+    {
+	// Check the types of the arguments.
+	argtypes = ((type_T **)stack->ga_data) + stack->ga_len - argcount;
+	if (internal_func_check_arg_types(argtypes, func_idx, argcount) == FAIL)
 	    return FAIL;
+    }
 
     if ((isn = generate_instr(cctx, ISN_BCALL)) == NULL)
 	return FAIL;