iOS arm64 support coming along nicely

[Dan Olson via digitalmars-d-ldc]

If anybody is feeling adventuresome and wants to try LDC with an arm64
iOS device, I updated the development repo with submodules that support
iOS arm64 and simulator.  I have tested on an iPhone 6 and all
druntime/phobos unittests pass with exception of some math results,
similar to what I documented for armv7.

https://github.com/smolt/ldc-iphone-dev

I haven't updated any of the readme files yet, but the build
instructions still apply.  The differences are that the dev repo will
pull in a llvm 3.6.1 with iOS TLS support, LDC is based on 0.15.2, and
fatlibs with all standard architectures (armv7, armv7s, arm64, i386, and
x86_64) are built for druntime and phobos.
-- 
Dan