Drop the const from the isa test.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@182178 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index a018718..a270976 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -161,7 +161,7 @@
              dyn_cast<const ObjCCategoryImplDecl>(DC)){
       OS << ((const NamedDecl *)OCD)->getIdentifier()->getNameStart() << '(' <<
           OCD->getIdentifier()->getNameStart() << ')';
-  } else if (isa<const ObjCProtocolDecl>(DC)) {
+  } else if (isa<ObjCProtocolDecl>(DC)) {
     // We can extract the type of the class from the self pointer.
     if (ImplicitParamDecl* SelfDecl = OMD->getSelfDecl()) {
       QualType ClassTy =