Fix simgrid-MC build

tests/model-checking/starpu_barrier.c

@@ -67,6 +67,7 @@
 #include <xbt/synchro_core.h>
 #endif
 
+/* common/thread.c references these, but doesn't need to have them working anyway */
 int
 _starpu_simgrid_thread_start(int argc, char *argv[])
 {
@@ -80,6 +81,10 @@ _starpu_simgrid_set_stack_size(size_t stack_size)
 {
 }
 
+starpu_sg_host_t _starpu_simgrid_get_host_by_name(const char *name)
+{
+}
+
 static void _starpu_clock_gettime(struct timespec *ts)
 {
 #ifdef HAVE_SIMGRID_GET_CLOCK