Cygwin: enable the use of Dl_info and dladdr()

These weren't available in Cygwin at the time our DSO code was
written, but things have changed since.

Fixes #9385
Reviewed-by: NMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9402)

crypto/dso/dso_dlfcn.c

@@ -27,8 +27,7 @@
 #  endif
 #  include <dlfcn.h>
 #  define HAVE_DLINFO 1
-#  if defined(__CYGWIN__) || \
-     defined(__SCO_VERSION__) || defined(_SCO_ELF) || \
+#  if defined(__SCO_VERSION__) || defined(_SCO_ELF) || \
      (defined(__osf__) && !defined(RTLD_NEXT))     || \
      (defined(__OpenBSD__) && !defined(RTLD_SELF)) || \
         defined(__ANDROID__)