Darwin/Mac64: Fix 64/32 size shortening warnings
Darwin/iOS prep script: try and compile for arm64
Darwin: Freshen prep scripts, remove old script
Darwin/iOS: Include x86_64+aarch64 pieces in library
Darwin: Properly export headers from Xcode project
Darwin/aarch64: Use CNAME refs
Darwin/aarch64: Fix invalid reference in assembly
Darwin/aarch64: Restrict .size to ELF like arm32.
Darwin/aarch64: Account for long double being equal to double

According to the iOS ABI Reference, long double is identical to
double in iOS, and will configure as such.
Darwin/aarch64: Inhibit Xcode warning
Darwin/aarch64: Use Clang cache invalidation builtin
Darwin/aarch64: Fix "shadows declaration" warnings
Darwin/aarch64: size_t assumptions