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/CodeGen/BranchFolding.h b/llvm/lib/CodeGen/BranchFolding.h
index 3653a2c..d1b17dd 100644
--- a/llvm/lib/CodeGen/BranchFolding.h
+++ b/llvm/lib/CodeGen/BranchFolding.h
@@ -142,6 +142,6 @@
     bool HoistCommonCode(MachineFunction &MF);
     bool HoistCommonCodeInSuccs(MachineBasicBlock *MBB);
   };
-}
+} // namespace llvm
 
 #endif /* LLVM_CODEGEN_BRANCHFOLDING_HPP */