a6324cb forget fix soft link in ENV folder, it cause superenv
use Apple provided git and svn.
ClosesHomebrew/homebrew#17927.
Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
stdenv already works as Contributions/cmds is in the path already.
This is safe to do because OS X already has git and svn in the PATH if you have the CLT installed. So we should definitely ensure we use the right versions.
FixesHomebrew/homebrew#15783.