Update Leopard/Tiger bottle tags

* PPC bottles are in the os_cpu format, e.g. :tiger_g3
* Intel bottles are the bare cat, as usual
* 64-bit bottles have _64 appended to them, e.g. :tiger_g5_64 or :leopard_64
lynx: fix --with-ssl for Xcode-only

Fixes #23423.
Massive commit squash encompassing all commits needed to:

* Get bottles building on 10.8 but running on 10.6
* Relocate .pc files intelligently
* Fix Homebrew tabs so we can detect in post_install when we've been poured from a bottle
* Do more aggressive binary file relocation