Implement redis_set_thread_title for MacOS.
Implement redis_set_thread_title for MacOS.

Strange enough, pthread_setname_np() produces a warning for not defined
function even if pthread is included. Moreover the MacOS documentation
claims the return value for the function is void, but actually is int.

Related to #7089.

yossigo/redis,ctripcorp/redis,neomantra/redis,antirez/redis,PKRoma/redis,ctripcorp/redis,neomantra/redis,oranagra/redis,neomantra/redis,PKRoma/redis,charsyam/redis,soloestoy/redis,ofirluzon/redis,soloestoy/redis,soloestoy/redis,oranagra/redis,charsyam/redis,yossigo/redis,PKRoma/redis,soloestoy/redis,charsyam/redis,antirez/redis,ofirluzon/redis,antirez/redis,neomantra/redis,oranagra/redis,yossigo/redis,soloestoy/redis,ofirluzon/redis,PKRoma/redis,oranagra/redis,oranagra/redis,antirez/redis,ofirluzon/redis,charsyam/redis,ctripcorp/redis,neomantra/redis,PKRoma/redis,ofirluzon/redis,yossigo/redis,charsyam/redis,yossigo/redis,ctripcorp/redis