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
diff --git a/llvm/lib/Transforms/Utils/LoopSimplify.cpp b/llvm/lib/Transforms/Utils/LoopSimplify.cpp
index d8f7c91..8b0afa6 100644
--- a/llvm/lib/Transforms/Utils/LoopSimplify.cpp
+++ b/llvm/lib/Transforms/Utils/LoopSimplify.cpp
@@ -776,7 +776,7 @@
     /// verifyAnalysis() - Verify LoopSimplifyForm's guarantees.
     void verifyAnalysis() const override;
   };
-}
+} // namespace
 
 char LoopSimplify::ID = 0;
 INITIALIZE_PASS_BEGIN(LoopSimplify, "loop-simplify",