gigi@gigi-VirtualBox:~$ arch
i686
gigi@gigi-VirtualBox:~$ uname -a
Linux gigi-VirtualBox 4.13.0-36-generic #40~16.04.1-Ubuntu SMP Fri Feb 16 23:26:51 UTC 2018 i686 i686 i686 GNU/Linux
gigi@gigi-VirtualBox:~$ local/Source/apple/build/Ninja-ReleaseAssert/swift-linux-i686/bin/swiftc hello.swift
gigi@gigi-VirtualBox:~$ ./hello
Hello, Swift!
gigi@gigi-VirtualBox:~$
Works! 
apple/swift repo from December 22, and libdispatch repo from today, but I guess I can do some clean up and make a PR.
@Joe_Groff How should I link compiler-rt ? I'm guessing it's done in CMakeLists.txt. Should I also link it in libdispatch? Would there be any implications to doing this? Also what's the difference between apple/swift-compiler-rt and the one already in llvm ?