R600: Handle amdgcn triple

For now there is no difference between amdgcn and r600.

llvm-svn: 225294
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index fb707f5..ef744d0 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -1522,6 +1522,7 @@
     return getSystemZTargetCPU(Args);
 
   case llvm::Triple::r600:
+  case llvm::Triple::amdgcn:
     return getR600TargetGPU(Args);
   }
 }
@@ -5472,6 +5473,7 @@
     .Cases("armv7s", "xscale", llvm::Triple::arm)
     .Case("arm64", llvm::Triple::aarch64)
     .Case("r600", llvm::Triple::r600)
+    .Case("amdgcn", llvm::Triple::amdgcn)
     .Case("nvptx", llvm::Triple::nvptx)
     .Case("nvptx64", llvm::Triple::nvptx64)
     .Case("amdil", llvm::Triple::amdil)