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
diff --git a/clang/lib/Frontend/Rewrite/FixItRewriter.cpp b/clang/lib/Frontend/Rewrite/FixItRewriter.cpp
index dc787ac..3b8a207 100644
--- a/clang/lib/Frontend/Rewrite/FixItRewriter.cpp
+++ b/clang/lib/Frontend/Rewrite/FixItRewriter.cpp
@@ -69,7 +69,7 @@
   }
 };
 
-}
+} // namespace
 
 bool FixItRewriter::WriteFixedFiles(
             std::vector<std::pair<std::string, std::string> > *RewrittenFiles) {
diff --git a/clang/lib/Frontend/Rewrite/HTMLPrint.cpp b/clang/lib/Frontend/Rewrite/HTMLPrint.cpp
index 22ccfe6..b270611 100644
--- a/clang/lib/Frontend/Rewrite/HTMLPrint.cpp
+++ b/clang/lib/Frontend/Rewrite/HTMLPrint.cpp
@@ -45,7 +45,7 @@
     void Initialize(ASTContext &context) override;
     void HandleTranslationUnit(ASTContext &Ctx) override;
   };
-}
+} // namespace
 
 std::unique_ptr<ASTConsumer> clang::CreateHTMLPrinter(raw_ostream *OS,
                                                       Preprocessor &PP,
diff --git a/clang/lib/Frontend/Rewrite/RewriteModernObjC.cpp b/clang/lib/Frontend/Rewrite/RewriteModernObjC.cpp
index e13cdb3..cfd790c 100644
--- a/clang/lib/Frontend/Rewrite/RewriteModernObjC.cpp
+++ b/clang/lib/Frontend/Rewrite/RewriteModernObjC.cpp
@@ -609,7 +609,7 @@
     }
   };
   
-}
+} // namespace
 
 void RewriteModernObjC::RewriteBlocksInFunctionProtoType(QualType funcType,
                                                    NamedDecl *D) {
diff --git a/clang/lib/Frontend/Rewrite/RewriteObjC.cpp b/clang/lib/Frontend/Rewrite/RewriteObjC.cpp
index b2a45b4..56f0606 100644
--- a/clang/lib/Frontend/Rewrite/RewriteObjC.cpp
+++ b/clang/lib/Frontend/Rewrite/RewriteObjC.cpp
@@ -540,7 +540,7 @@
                                       std::string &Result) override;
     Stmt *RewriteObjCIvarRefExpr(ObjCIvarRefExpr *IV) override;
   };
-}
+} // namespace
 
 void RewriteObjC::RewriteBlocksInFunctionProtoType(QualType funcType,
                                                    NamedDecl *D) {