Make Rust work on OS X 10.5

[brson]

There are some atomic intrinsics missing in the default compiler (4.0 something) but with newer gcc's or clangs it should be possible. There are some leads in a mailing list thread.

[brson]

https://mail.mozilla.org/pipermail/rust-dev/2012-December/002754.html
https://mail.mozilla.org/pipermail/rust-dev/2012-December/002755.html

[kud1ing]

Chrome and Firefox stopped supporting OSX 10.5 in 2012. Its successor 10.6 is now (pre Rust 0.6) available for 3.5 years. In Omnigroup's statistic http://update.omnigroup.com/ OS X 10.5's share is around/below 10%

Do you think we should keep this issue?

[cooljeanius]

Is this still broken on 10.5? I'm trying to decide whether to remove 10.5 support from Rust's MacPorts portfile...

[brson]

@cooljeanius It's still broken and there doesn't seem to be much interest in fixing, so I think removing it from the macport is appropriate.

[larryv]

@brson Is it broken because of something inherent to 10.5, or is the issue with 10.5’s compilers? We (MacPorts) can build ports using our own compiler ports, so the distinction is important.

[catamorphism]

Lack of activity and old OS version; closing.

[cooljeanius]

I suppose closing this is ok, MacPorts already went and removed 10.5 support from the Rust portfile anyways...
(https://trac.macports.org/changeset/104169)

[steveklabnik]

Most Mac people use Homebrew these days anyway. (Citation, of course, needed. I haven't heard anyone talk about macports in a looooooong time, but given Homebrew is written in Ruby, that could just be bias.)