Make OSSL_provider_init() OPENSSL_EXPORT, not just extern
On non-Windows systems, there's no difference at all.  On Windows systems,
__declspec(dllexport) is added, which ensures it gets exported no matter
what.
Fixes
@@ -195,7 +195,7 @@ typedef int (OSSL_provider_init_fn)(const OSSL_CORE_HANDLE *handle,
# pragma names save
# pragma names uppercase,truncated
# endif
-extern OSSL_provider_init_fn OSSL_provider_init;
+OPENSSL_EXPORT OSSL_provider_init_fn OSSL_provider_init;
# ifdef __VMS
# pragma names restore
# endif
