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/unit1616.c

@@ -27,8 +27,6 @@
 #include <uint-hash.h>
 #include <memdebug.h> /* LAST include file */
 
-static struct uint_hash t1616_hash_static;
-
 static void t1616_mydtor(unsigned int id, void *elem)
 {
   int *ptr = (int *)elem;
@@ -36,18 +34,23 @@ static void t1616_mydtor(unsigned int id, void *elem)
   free(ptr);
 }
 
-static CURLcode unit_setup(void)
+static CURLcode t1616_setup(struct uint_hash *hash)
 {
-  Curl_uint_hash_init(&t1616_hash_static, 15, t1616_mydtor);
+  Curl_uint_hash_init(hash, 15, t1616_mydtor);
   return CURLE_OK;
 }
 
-static void unit_stop(void)
+static void t1616_stop(struct uint_hash *hash)
 {
-  Curl_uint_hash_destroy(&t1616_hash_static);
+  Curl_uint_hash_destroy(hash);
 }
 
-UNITTEST_START
+static CURLcode test_unit1616(char *arg)
+{
+  struct uint_hash hash;
+
+  UNITTEST_BEGIN(t1616_setup(&hash))
+
   int *value, *v;
   int *value2;
   bool ok;
@@ -55,31 +58,31 @@ UNITTEST_START
   unsigned int key = 20;
   unsigned int key2 = 25;
 
-
   value = malloc(sizeof(int));
   abort_unless(value != NULL, "Out of memory");
   *value = 199;
-  ok = Curl_uint_hash_set(&t1616_hash_static, key, value);
+  ok = Curl_uint_hash_set(&hash, key, value);
   if(!ok)
     free(value);
   abort_unless(ok, "insertion into hash failed");
-  v = Curl_uint_hash_get(&t1616_hash_static, key);
+  v = Curl_uint_hash_get(&hash, key);
   abort_unless(v == value, "lookup present entry failed");
-  v = Curl_uint_hash_get(&t1616_hash_static, key2);
+  v = Curl_uint_hash_get(&hash, key2);
   abort_unless(!v, "lookup missing entry failed");
-  Curl_uint_hash_clear(&t1616_hash_static);
+  Curl_uint_hash_clear(&hash);
 
   /* Attempt to add another key/value pair */
   value2 = malloc(sizeof(int));
   abort_unless(value2 != NULL, "Out of memory");
   *value2 = 204;
-  ok = Curl_uint_hash_set(&t1616_hash_static, key2, value2);
+  ok = Curl_uint_hash_set(&hash, key2, value2);
   if(!ok)
     free(value2);
   abort_unless(ok, "insertion into hash failed");
-  v = Curl_uint_hash_get(&t1616_hash_static, key2);
+  v = Curl_uint_hash_get(&hash, key2);
   abort_unless(v == value2, "lookup present entry failed");
-  v = Curl_uint_hash_get(&t1616_hash_static, key);
+  v = Curl_uint_hash_get(&hash, key);
   abort_unless(!v, "lookup missing entry failed");
 
-UNITTEST_STOP
+  UNITTEST_END(t1616_stop(&hash))
+}