Revert "Deautocrap: everybody has a pthread_setname_np(2) now."

This reverts commit 41cdd27.

Even though everybody has a pthread_setname_np(3), they are different
and not portable by definition. The safeguards should be preserved
since THR_SetName() will at least allow a panic to get the thread name.

bin/varnishd/cache/cache_main.c

@@ -152,13 +152,17 @@ THR_SetName(const char *name)
 {
 
 	PTOK(pthread_setspecific(name_key, name));
+#if defined(HAVE_PTHREAD_SET_NAME_NP)
+	pthread_set_name_np(pthread_self(), name);
+#elif defined(HAVE_PTHREAD_SETNAME_NP)
 #if defined(__APPLE__)
 	(void)pthread_setname_np(name);
 #elif defined(__NetBSD__)
 	(void)pthread_setname_np(pthread_self(), "%s", (char *)(uintptr_t)name);
 #else
 	thr_setname_generic(name);
 #endif
+#endif
 }
 
 const char *

configure.ac

@@ -227,6 +227,8 @@ AC_CHECK_FUNCS([fnmatch], [], [AC_MSG_ERROR([fnmatch(3) is required])])
 
 save_LIBS="${LIBS}"
 LIBS="${PTHREAD_LIBS}"
+AC_CHECK_FUNCS([pthread_set_name_np])
+AC_CHECK_FUNCS([pthread_setname_np])
 AC_CHECK_FUNCS([pthread_mutex_isowned_np])
 AC_CHECK_FUNCS([pthread_getattr_np])
 LIBS="${save_LIBS}"