urlapi: turn three local-only functions into statics
conncache: make conncache_find_first_connection static
multi: make detach_connnection static
connect: make getaddressinfo static
curl_ntlm_core: make hmac_md5 static
http2: make two functions static
http: make http_setup_conn static
connect: make tcpnodelay static
tests: make UNITTEST a thing to mark functions with, so they can be static for
normal builds and non-static for unit test builds
... and mark Curl_shuffle_addr accordingly.
url: make up_free static
setopt: make vsetopt static
curl_endian: make write32_le static
rtsp: make rtsp_connisdead static
warnless: remove unused functions
memdebug: remove one unused function, made another static
This enables users to preresolve but still take advantage of happy
eyeballs and trying multiple addresses if some are not connecting.
Ref: https://github.com/curl/curl/pull/2260
