Make the ObjCLanguageRuntimes comply with llvm-style RTTI

llvm-svn: 248427
diff --git a/lldb/source/Plugins/Language/ObjC/NSArray.cpp b/lldb/source/Plugins/Language/ObjC/NSArray.cpp
index c6db27e..a851699 100644
--- a/lldb/source/Plugins/Language/ObjC/NSArray.cpp
+++ b/lldb/source/Plugins/Language/ObjC/NSArray.cpp
@@ -624,7 +624,7 @@
     lldb::ProcessSP process_sp (valobj_sp->GetProcessSP());
     if (!process_sp)
         return NULL;
-    AppleObjCRuntime *runtime = (AppleObjCRuntime*)process_sp->GetLanguageRuntime(lldb::eLanguageTypeObjC);
+    AppleObjCRuntime *runtime = llvm::dyn_cast_or_null<AppleObjCRuntime>(process_sp->GetObjCLanguageRuntime());
     if (!runtime)
         return NULL;