general update

c_extern.sl

@@ -0,0 +1,13 @@
+import stdlib/io.sl
+
+# C-style externs (auto ABI handling)
+extern long labs(long n)
+extern void exit(int status)
+
+: main
+    # Test C-style extern with implicit ABI handling
+    -10 labs puti cr
+    
+    # Test extern void
+    0 exit
+;