Add regression test. Closes #1486

Author: michael-schwarz

tests/regression/46-apron2/97-std-globals.c

@@ -0,0 +1,21 @@
+// SKIP PARAM: --set ana.activated[+] apron  --set ana.relation.privatization mutex-meet --sets ana.apron.domain interval
+// Checks that branching over extern or volatile variables does not yield to both branches being dead.
+#include<pthread.h>
+extern int optind;
+
+void* a(void* arg) {
+  // Just go multi-threaded
+}
+
+void main() {
+  pthread_t t;
+
+
+  pthread_create(&t, 0, a, 0);
+
+  if (optind) {
+
+  }
+
+  __goblint_check(1); // Reachable
+}