Update our mono to a modern version. The one in ports currently is an
early release of the 5.x branch and is very buggy. I see lots of crashes
that never used to happen with 4.8.
This version builds and packages and is using BoringSSL
TODO:
* Enable jemalloc from base if possible **edit: I think the jemalloc from base is already used and compiling in jemalloc support is not necessary**
* Tests?
* Figure out if any of the old patches from D14006 are worth keeping
** I removed all of those patches after conferring with the guy who
ported Mono to AIX recently and something in there was also causing
failures. **edit: some patches have been resurrected**
Also he strongly recommends against us trying to make "freebsd" verb a
supported platform. Even his AIX builds piggyback on the "linux" verb.
It seems to cause needless complexity. (I might be using wrong
terminology here; I don't grok build frameworks very well)
I also have a patch that fixes an issue with freebsd building with a
newer version of corefx, but that seems to only occur if we try to build
mono HEAD.