Update the test framework so that the need for test_main is removed.  Everything
that needed test_main now works using the same infrastructure as tests that used
register_tests.

This meant:
* renaming register_tests to setup_tests and giving it a success/failure return.
* renaming the init_test function to setup_test_framework.
* renaming the finish_test function to pulldown_test_framework.
* adding a user provided global_init function that runs before the test frame
    work is initialised.  It returns a failure indication that stops the stest.
* adding helper functions that permit tests to access their command line args.
* spliting the BIO initialisation and finalisation out from the test setup and
    teardown.
* hiding some of the now test internal functions.
* fix the comments in testutil.h

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3953)
diff --git a/test/bftest.c b/test/bftest.c
index df2c9a7..cc509f2 100644
--- a/test/bftest.c
+++ b/test/bftest.c
@@ -435,7 +435,7 @@
 }
 #endif
 
-int test_main(int argc, char *argv[])
+int setup_tests(void)
 {
 #ifndef OPENSSL_NO_BF
 # ifdef CHARSET_EBCDIC
@@ -447,15 +447,16 @@
     }
 # endif
 
-    ADD_ALL_TESTS(test_bf_ecb_raw, 2);
-    ADD_ALL_TESTS(test_bf_ecb, NUM_TESTS);
-    ADD_ALL_TESTS(test_bf_set_key, KEY_TEST_NUM-1);
-    ADD_TEST(test_bf_cbc);
-    ADD_TEST(test_bf_cfb64);
-    ADD_TEST(test_bf_ofb64);
-
-    if (argc > 1)
-        return print_test_data();
+    if (test_get_argument(0) != NULL) {
+        print_test_data();
+    } else {
+        ADD_ALL_TESTS(test_bf_ecb_raw, 2);
+        ADD_ALL_TESTS(test_bf_ecb, NUM_TESTS);
+        ADD_ALL_TESTS(test_bf_set_key, KEY_TEST_NUM-1);
+        ADD_TEST(test_bf_cbc);
+        ADD_TEST(test_bf_cfb64);
+        ADD_TEST(test_bf_ofb64);
+    }
 #endif
-    return run_tests(argv[0]);
+    return 1;
 }