nac3standalone: add output_long

nac3standalone/demo/classes.py

@@ -2,6 +2,10 @@
 def output_int(x: int32):
     ...
 
+@extern
+def output_long(x: int64):
+    ...
+
 
 class A:
     a: int32

nac3standalone/demo/demo.c

@@ -5,6 +5,10 @@ void output_int(int x) {
     printf("%d\n", x);
 }
 
+void output_long(long x) {
+    printf("%ld\n", x);
+}
+
 void output_asciiart(int x) {
     static char chars[] = " .,-:;i+hHM$*#@  ";
     if(x < 0) {