[AMDGPU] Add builtin functions readlane ds_permute mov_dpp

Differential Revision: https://reviews.llvm.org/D30551

llvm-svn: 297436
diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp
index 6b0b910..e23ff3c 100644
--- a/clang/lib/Basic/Targets.cpp
+++ b/clang/lib/Basic/Targets.cpp
@@ -2387,6 +2387,7 @@
     case GK_GFX8:
       Features["s-memrealtime"] = true;
       Features["16-bit-insts"] = true;
+      Features["dpp"] = true;
       break;
 
     case GK_NONE: