These flags are potentially risky, because they require that the app explicitly
initialize stuff that it wouldn't otherwise need to initialize, and we don't
have time for the necessary review.
This passes `-Wa,--noexecstack` to the assembler when building
platform-specific assembly files, to signal that a non-executable stack
can be used. This is the same approach as used by Debian
(see https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=430583)
Rebased-From: bfcdc21a5da25ec1aa4aecc4cd8960dfa1c11781
Github-Pull: #6852
Bumps the OpenSSL version to the latest release, and kills SSL2. (SSL3 was already killed here, so I'm not sure why SSL2 was left around?)
No other changes.