Add FOLLY_OPENSSL_HAS_ALPN and FOLLY_OPENSSL_HAS_SNI.
Summary:
This expresses the intention of long predicate on OpenSSL version and
OPENSSL_NO_TLSEXT more clearly.
This also enables ALPN and SNI support when BoringSSL is in use.
ALPN is an essential function to make HTTP/2 work when building Proxygen
with BoringSSL.
Closes https://github.com/facebook/folly/pull/534
Reviewed By: Orvid
Differential Revision:
D4375391
Pulled By: yfeldblum
fbshipit-source-id:
009f311bceb0ee911d904d96a3e678a5f7241575