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

The patch is generated using this command:

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

To reduce churn, not touching namespaces spanning less than 10 lines.

llvm-svn: 240270

clang/lib/Frontend/DependencyGraph.cpp

@@ -57,7 +57,7 @@ public:
   }
   
 };
-}
+} // namespace
 
 void clang::AttachDependencyGraphGen(Preprocessor &PP, StringRef OutputFile,
                                      StringRef SysRoot) {