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/Sema/SemaDeclObjC.cpp b/clang/lib/Sema/SemaDeclObjC.cpp
index 543566f..6ca4734 100644
--- a/clang/lib/Sema/SemaDeclObjC.cpp
+++ b/clang/lib/Sema/SemaDeclObjC.cpp
@@ -446,7 +446,7 @@
   ObjCInterfaceDecl *CurrentIDecl;
 };
 
-}
+} // namespace
 
 static void diagnoseUseOfProtocols(Sema &TheSema,
                                    ObjCContainerDecl *CD,
@@ -3059,7 +3059,7 @@
     searchFromContainer(container);
   }
 };
-}
+} // namespace
 
 void Sema::CheckObjCMethodOverrides(ObjCMethodDecl *ObjCMethod,
                                     ObjCInterfaceDecl *CurrentClass,
@@ -3717,7 +3717,7 @@
       return true;
     }
   };
-}
+} // namespace
 
 void Sema::DiagnoseUnusedBackingIvarInAccessor(Scope *S,
                                           const ObjCImplementationDecl *ImplD) {