Prefix all size_t with std::

done automatically by executing regex replace `([^:0-9a-zA-Z_])size_t([^0-9a-zA-Z_])` -> `$1std::size_t$2`

src/common/logging/backend.h

@@ -101,7 +101,7 @@ public:
 
 private:
     FileUtil::IOFile file;
-    size_t bytes_written;
+    std::size_t bytes_written;
 };
 
 void AddBackend(std::unique_ptr<Backend> backend);