[Bug target/63810] gcc sets incorrect macro for OS X deployment targets

[larryv at macports dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63810

--- Comment #2 from Lawrence Velázquez <larryv at macports dot org> ---
(In reply to Jeremy Huddleston Sequoia from comment #1)
> Larry said that he's working on a patch to fix this for gcc trunk, and I
> suspect he's pretty close to having something since that was about a week
> ago.

I just completed the fix and will attach it as soon as I verify that GCC builds
with it and that the tests I added pass.