nac3standalone: add dummy support for artiq_personality

So existing tests can run again

nac3standalone/demo/demo.rs

@@ -53,6 +53,11 @@ pub extern "C" fn output_int32_list(x: &cslice::CSlice<i32>) {
     println!("]");
 }
 
+#[no_mangle]
+pub extern "C" fn __artiq_personality(_state: u32, _exception_object: u32, _context: u32) -> u32 {
+    unimplemented!();
+}
+
 
 extern "C" {
     fn run() -> i32;

nac3standalone/demo/run_demo.sh

@@ -16,5 +16,5 @@ fi
 
 rm -f *.o
 $nac3standalone $1
-rustc -o demo demo.rs -Clink-arg=./module.o
+rustc -o demo demo.rs -Crelocation-model=static -Clink-arg=./module.o
 ./demo