LDC 1.9.0 beta

[kinke]

Hi everyone,

on behalf of the LDC team, I'm glad to announce the first beta 
for LDC 1.9. The highlights of this version in a nutshell:

* Based on D 2.079.1, including new `-i` switch and support for a 
minimal (d)runtime.
* Support for LLVM 6, used for all prebuilt packages (except for 
Win32).
* `-link-internally` able to (cross-)link Windows, Linux and 
macOS binaries.
* Prebuilt Linux and macOS packages now shipping with LTO-able 
druntime/Phobos.
* Improved support for MIPS targets and the uClibc runtime 
library.
* Various fixes, incl. druntime/Phobos/ldc-jit .dylib issues on 
macOS.

Full release log and downloads: 
https://github.com/ldc-developers/ldc/releases/tag/v1.9.0-beta1

Thanks to all contributors!