tests: always make bundles, adapt build and tests

Make test bundles the default. Drop non-bundle build mode.
Also do all the optimizations and tidy-ups this allows, simpler builds,
less bundle exceptions, streamlined build mechanics.

Also rework the init/deinit macro magic for unit tests. The new method
allows using unique init/deinit function names, and calling them with
arguments. This is in turn makes it possible to reduce the use of global
variables.

Note this drop existing build options `-DCURL_TEST_BUNDLES=` from cmake
and `--enable-test-bundles` / `--disable-test-bundles` from autotools.

Also:
- rename test entry functions to have unique names: `test_<testname>`
  This removes the last exception that was handled in the generator.
- fix `make dist` to not miss test sources with test bundles enabled.
- sync and merge `tests/mk-bundle.pl` into `scripts/mk-unity.pl`.
- mk-unity.pl: add `--embed` option and use it when `CURL_CLANG_TIDY=ON`
  to ensure that `clang-tidy` does not miss external test C sources.
  (because `clang-tidy` ignores code that's #included.)
- tests/unit: drop no-op setup/stop functions.
- tests: reduce symbol scopes, global macros, other fixes and tidy-ups.
- tool1621: fix to run, also fix it to pass.
- sockfilt: fix Windows compiler warning in certain unity include order,
  by explicitly including `warnless.h`.

Follow-up to 6897aeb105 #17468

Closes #17590

tests/unit/unit1303.c

@@ -27,24 +27,22 @@
 #include "connect.h"
 #include "memdebug.h" /* LAST include file */
 
-static struct Curl_easy *t1303_easy;
-
-static CURLcode unit_setup(void)
+static CURLcode t1303_setup(struct Curl_easy **easy)
 {
   CURLcode res = CURLE_OK;
 
   global_init(CURL_GLOBAL_ALL);
-  t1303_easy = curl_easy_init();
-  if(!t1303_easy) {
+  *easy = curl_easy_init();
+  if(!*easy) {
     curl_global_cleanup();
     return CURLE_OUT_OF_MEMORY;
   }
   return res;
 }
 
-static void unit_stop(void)
+static void t1303_stop(struct Curl_easy *easy)
 {
-  curl_easy_cleanup(t1303_easy);
+  curl_easy_cleanup(easy);
   curl_global_cleanup();
 }
 
@@ -55,8 +53,8 @@ static void unit_stop(void)
 /* macro to set the pretended current time */
 #define NOW(x,y) now.tv_sec = x; now.tv_usec = y
 /* macro to set the millisecond based timeouts to use */
-#define TIMEOUTS(x,y) t1303_easy->set.timeout = x; \
-                      t1303_easy->set.connecttimeout = y
+#define TIMEOUTS(x,y) easy->set.timeout = x; \
+                      easy->set.connecttimeout = y
 
 /*
  * To test:
@@ -67,21 +65,25 @@ static void unit_stop(void)
  * N           various values of now
  */
 
-struct timetest {
-  int now_s;
-  int now_us;
-  unsigned int timeout_ms;
-  unsigned int connecttimeout_ms;
-  bool connecting;
-  timediff_t result;
-  const char *comment;
-};
-
-UNITTEST_START
+static CURLcode test_unit1303(char *arg)
 {
+  struct Curl_easy *easy;
+
+  UNITTEST_BEGIN(t1303_setup(&easy))
+
   struct curltime now;
   unsigned int i;
 
+  struct timetest {
+    int now_s;
+    int now_us;
+    unsigned int timeout_ms;
+    unsigned int connecttimeout_ms;
+    bool connecting;
+    timediff_t result;
+    const char *comment;
+  };
+
   const struct timetest run[] = {
   /* both timeouts set, not connecting */
   {BASE + 4, 0,      10000, 8000, FALSE, 6000, "6 seconds should be left"},
@@ -137,18 +139,19 @@ UNITTEST_START
   };
 
   /* this is the pretended start time of the transfer */
-  t1303_easy->progress.t_startsingle.tv_sec = BASE;
-  t1303_easy->progress.t_startsingle.tv_usec = 0;
-  t1303_easy->progress.t_startop.tv_sec = BASE;
-  t1303_easy->progress.t_startop.tv_usec = 0;
+  easy->progress.t_startsingle.tv_sec = BASE;
+  easy->progress.t_startsingle.tv_usec = 0;
+  easy->progress.t_startop.tv_sec = BASE;
+  easy->progress.t_startop.tv_usec = 0;
 
   for(i = 0; i < CURL_ARRAYSIZE(run); i++) {
     timediff_t timeout;
     NOW(run[i].now_s, run[i].now_us);
     TIMEOUTS(run[i].timeout_ms, run[i].connecttimeout_ms);
-    timeout =  Curl_timeleft(t1303_easy, &now, run[i].connecting);
+    timeout =  Curl_timeleft(easy, &now, run[i].connecting);
     if(timeout != run[i].result)
       fail(run[i].comment);
   }
+
+  UNITTEST_END(t1303_stop(easy))
 }
-UNITTEST_STOP