Define Contiki OS toolchain

Patch by Michael LeMay

Differential revision: http://reviews.llvm.org/D19854

llvm-svn: 284278
diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index 459f601..f2ee1ca 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -3120,6 +3120,9 @@
     case llvm::Triple::PS4:
       TC = new toolchains::PS4CPU(*this, Target, Args);
       break;
+    case llvm::Triple::Contiki:
+      TC = new toolchains::Contiki(*this, Target, Args);
+      break;
     default:
       // Of these targets, Hexagon is the only one that might have
       // an OS of Linux, in which case it got handled above already.