drop __ in Declspec

Author: shiltian

clang/include/clang/Basic/Attr.td

@@ -1573,15 +1573,15 @@ def HIPManaged : InheritableAttr {
 }
 
 def CUDAClusterDims : InheritableAttr {
-  let Spellings = [GNU<"cluster_dims">, Declspec<"__cluster_dims__">];
+  let Spellings = [GNU<"cluster_dims">, Declspec<"cluster_dims">];
   let Args = [ExprArgument<"X">, ExprArgument<"Y", 1>, ExprArgument<"Z", 1>];
   let Subjects = SubjectList<[ObjCMethod, FunctionLike]>;
   let LangOpts = [CUDA];
   let Documentation = [CUDAClusterDimsAttrDoc];
 }
 
 def CUDANoCluster : InheritableAttr {
-  let Spellings = [GNU<"no_cluster">, Declspec<"__no_cluster__">];
+  let Spellings = [GNU<"no_cluster">, Declspec<"no_cluster">];
   let Subjects = SubjectList<[ObjCMethod, FunctionLike]>;
   let LangOpts = [CUDA];
   let Documentation = [CUDANoClusterAttrDoc];