refactored the testing system, fixed fput and removed arr_asm.sl

extra_tests/c_extern.sl

@@ -0,0 +1,23 @@
+import stdlib.sl
+import float.sl
+
+# C-style externs (auto ABI handling)
+extern long labs(long n)
+extern void exit(int status)
+extern double atan2(double y, double x)
+
+word main
+    # Test C-style extern with implicit ABI handling
+    -10 labs puti cr
+
+    1.5 2.5 f+              # 4.0
+    fputln
+
+    # External math library (libm)
+    10.0 10.0 atan2         # Result is pi/4
+    4.0 f*                  # Approx pi
+    fputln
+
+    # Test extern void
+    0 exit
+end