Remove spurious default case to silent sanitizer

llvm-svn: 201309

clang/lib/Driver/Tools.cpp

@@ -6564,8 +6564,6 @@ static void AddRunTimeLibs(const ToolChain &TC, const Driver &D,
   case ToolChain::RLT_Libgcc:
     AddLibgcc(TC.getTriple(), D, CmdArgs, Args);
     break;
-  default:
-    llvm_unreachable("Unknown RT-Lib type");
   }
 }