build: Keep an autoconf check for pthread_setname_np()

[dridi]

It is not portable by definition, so we should keep the guards.

[bsdphk]

First apologies for confusing everybody with a sign-error on the underscore

There is no reason to retain this check because all relevant platforms today have pthread_setname_np() and if somebody wants to port varnish to a new platform, they will have to provide a pthread_setname_np() function.

Please also note that the "_np" suffix literally means "POSIX is stuck in the 1990'ies where some people ran VMS", it doesnt mean that all contemporary platforms do not have it.

[nigoroll]

FTR, I just hit this on a not-so-recent SmartOS

cache/cache_main.c: In function 'THR_SetName':
cache/cache_main.c:142:2: error: implicit declaration of function 'pthread_setname_np' [-Werror=implicit-function-declaration]
  (void)pthread_setname_np(pthread_self(), name);
  ^

[dridi]

The THR_SetName() function still serves the purpose of stashing the thread name that is displayed in a panic in the absence of pthread_setname_np().

[catap]

FYI: Just hit this on OpenBSD.

[nigoroll]

bugwash: @walid-git to resolve conflicts and merge