Add CodeGen support for the nodebug attribute.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@64445 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index 4bca3d9..833a52b 100644
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -1310,8 +1310,8 @@
     S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments) << 0;
     return;
   }
-  FunctionDecl *Fn = dyn_cast<FunctionDecl>(d);
-  if (!Fn) {
+
+  if (!isa<FunctionDecl>(d)) {
     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
       << "nodebug" << "function";
     return;