am 1a6939d2: am 1e0a4e18: Merge "stdio: make internal symbols static/hidden"

Merge commit '1a6939d27b1cc53d506d6583fa2bc2d90c9c7fc4'

* commit '1a6939d27b1cc53d506d6583fa2bc2d90c9c7fc4':
  stdio: make internal symbols static/hidden