tidy-up: miscellaneous

- apply more clang-format.
- lib/version: use `CURL_ARRAYSIZE()`.
- INSTALL-CMAKE.md: sync-up an option description with others.
- examples: delete unused main args.
- examples/ftpgetinfo: document `_CRT_SECURE_NO_WARNINGS` symbol.
- delete remaining stray duplicate lines.
- acinclude.m4: drop an unnecessary x-hack.
- vtls/mbedtls: join a URL split into two lines.
- src/tool_cb_see: add parentheses around macro expressions.
- src/tool_operate: move literals to the right side of comparisons.
- libtests: sync up fopen/fstat error messages between tests.
- curl_setup.h: replace `if ! defined __LP64` with `ifndef __LP64`.
  I assume it makes no difference on Tandem systems, as the latter form
  is already used in `include/curl/system.h`.

Closes #20018

docs/examples/ephiperfifo.c

@@ -451,15 +451,13 @@ void sigint_handler(int signo)
   g_should_exit_ = 1;
 }
 
-int main(int argc, char **argv)
+int main(void)
 {
   CURLcode result;
   struct GlobalInfo g;
   struct itimerspec its;
   struct epoll_event ev;
   struct epoll_event events[10];
-  (void)argc;
-  (void)argv;
 
   result = curl_global_init(CURL_GLOBAL_ALL);
   if(result)