Merge changes If317bf19,Ie8b5bc0e,Iaa8c88aa,Idab7680c
am: f3cbb4c77d

* commit 'f3cbb4c77dd9846b611f8dde636d6b0ac344ea23':
  Remove symbols that are not present in platform libc
  Remove LIBC_PRIVATE symbols from android-21 libdl
  Remove LIBC_PRIVATE symbols from android-21 libm
  Remove LIBC_PRIVATE symbols from android-21 libc