Un-break s_lock_test.

Commit 80abbeba2 evidently didn't bother checking this code.
Also, list the generated executable in .gitignore (so it's
been a REALLY long time since anyone tried this).

Noted while trying out RISC-V spinlock patch.  Given that
this has been broken for 5 years and nobody noticed, it's
likely not worth back-patching.

src/backend/storage/lmgr/.gitignore

@@ -1,2 +1,3 @@
 /lwlocknames.c
 /lwlocknames.h
+/s_lock_test

src/backend/storage/lmgr/s_lock.c

@@ -368,7 +368,7 @@ main()
 	printf("             if S_LOCK() and TAS() are working.\n");
 	fflush(stdout);
 
-	s_lock(&test_lock.lock, __FILE__, __LINE__);
+	s_lock(&test_lock.lock, __FILE__, __LINE__, PG_FUNCNAME_MACRO);
 
 	printf("S_LOCK_TEST: failed, lock not locked\n");
 	return 1;