Cherry pick of Windows thread-safety fixes from develop

test/thread_id.c

@@ -25,6 +25,8 @@
  */
 #include "testhdf5.h"
 
+#if defined(H5_HAVE_THREADSAFE) && !defined(H5_HAVE_WIN_THREADS)
+
 static void my_errx(int, const char *, ...) H5_ATTR_FORMAT(printf, 2, 3);
 
 static void
@@ -40,8 +42,6 @@ my_errx(int code, const char *fmt, ...)
     HDexit(code);
 }
 
-#if defined(H5_HAVE_THREADSAFE) && !defined(H5_HAVE_WIN_THREADS)
-
 #if defined(H5_HAVE_DARWIN)
 
 typedef struct _pthread_barrierattr {