AMDGPU/NFC: Remove SubtargetFeatureISAVersion since it is not used anywhere


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@353892 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/AMDGPU/AMDGPU.td b/lib/Target/AMDGPU/AMDGPU.td
index e37fd0a..0b0c125 100644
--- a/lib/Target/AMDGPU/AMDGPU.td
+++ b/lib/Target/AMDGPU/AMDGPU.td
@@ -470,16 +470,6 @@
   ]
 >;
 
-class SubtargetFeatureISAVersion <int Major, int Minor, int Stepping,
-                                  list<SubtargetFeature> Implies>
-                                 : SubtargetFeature <
-  "isaver"#Major#"."#Minor#"."#Stepping,
-  "IsaVersion",
-  "ISAVersion"#Major#"_"#Minor#"_"#Stepping,
-  "Instruction set version number",
-  Implies
->;
-
 class FeatureSet<list<SubtargetFeature> Features_> {
   list<SubtargetFeature> Features = Features_;
 }