Fixed/added namespace ending comments using clang-tidy. NFC

The patch is generated using this command:

tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
  -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
  llvm/lib/


Thanks to Eugene Kosov for the original patch!

llvm-svn: 240137

llvm/lib/Bitcode/Writer/ValueEnumerator.cpp

@@ -52,7 +52,7 @@ struct OrderMap {
     IDs[V].first = ID;
   }
 };
-}
+} // namespace
 
 static void orderValue(const Value *V, OrderMap &OM) {
   if (OM.lookup(V).first)