Prefix/Darwin

General

 * macOS follows the normal bootstrap procedure
 * Bootstraps currently done via GCC
 * host/Apple Clang from xcode tools is used then GCC is built as soon as possible
 * Using GCC as the "system" compiler within Prefix has problems
 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90709 (general tracker for macOS header/frameworks issues with GCC)
 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78352 (Blocks support)
 * As a result, can't build things using e.g. Aqua (nice GUI) integrations or other Frameworks (e.g. git keychain integration).
 * We use the system (host) linker because we can't build Apple's linker independently within our prefix without Clang, because it uses Blocks
 * Possibility of bootstrapping via Clang?
 * It's doable!
 * Needs some work to get sysroot, SDK paths right. See what e.g. macports does for hints.
 * is the meta bug for this work.
 * Help very much welcome!

arm64-macos
M1 macs, etc.

Cannot currently be bootstrapped:
 * Waiting for GCC support to be merged upstream and in a release (GCC 12?)
 * See https://github.com/iains/gcc-darwin-arm64
 * With a snapshot of the GCC fork/branch, we can get a bit further, but bootstrapping doesn't complete.
 * - Prefix: Big Sur ARM (M1 MacBook Pro MYD82LL/A) build failure due to missing symbols
 * - fails to build during prefix bootstrap on M1 (Big Sur 11.4)

x64-macos
Works okay!