download: Do not wrap TLS port on GnuTLS >= 3.7.7.

The custom input/output port wrapping the TLS session record port would
introduce overhead, and it would also prevent its uses in a non-blocking
context--e.g., with Fibers.  The port close mechanism added in GnuTLS
3.7.7 allows us to get rid of that wrapper.

* guix/build/download.scm (wrap-record-port-for-gnutls<3.7.7): New
procedure, with code formerly in 'tls-wrap'.
(tls-wrap): Check for 'set-session-record-port-close!' and use it when
available; otherwise call 'wrap-record-port-for-gnutls<3.7.7'.

0 files changed, 0 insertions, 0 deletions