Add support for the VSX target attribute. No functional change
as we don't actually use it to emit any code yet.

llvm-svn: 192837
diff --git a/llvm/lib/Target/PowerPC/PPC.td b/llvm/lib/Target/PowerPC/PPC.td
index 57ee264..54e3d40 100644
--- a/llvm/lib/Target/PowerPC/PPC.td
+++ b/llvm/lib/Target/PowerPC/PPC.td
@@ -87,6 +87,8 @@
                                         "Enable Book E instructions">;
 def FeatureQPX       : SubtargetFeature<"qpx","HasQPX", "true",
                                         "Enable QPX instructions">;
+def FeatureVSX       : SubtargetFeature<"vsx","HasVSX", "true",
+                                        "Enable VSX instructions">;
 
 def DeprecatedMFTB   : SubtargetFeature<"", "DeprecatedMFTB", "true",
                                         "Treat mftb as deprecated">;