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!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240137 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Support/MemoryBuffer.cpp

@@ -94,7 +94,7 @@ public:
     return MemoryBuffer_Malloc;
   }
 };
-}
+} // namespace
 
 static ErrorOr<std::unique_ptr<MemoryBuffer>>
 getFileAux(const Twine &Filename, int64_t FileSize, uint64_t MapSize, 
@@ -220,7 +220,7 @@ public:
     return MemoryBuffer_MMap;
   }
 };
-}
+} // namespace
 
 static ErrorOr<std::unique_ptr<MemoryBuffer>>
 getMemoryBufferForStream(int FD, const Twine &BufferName) {