KNOWN ABI BUGS
--------------

  time_t is 32-bit. http://b/5819737

  off_t is 32-bit. There is off64_t, but no _FILE_OFFSET_BITS support.

  sigset_t is too small on ARM and x86 (but correct on MIPS), so support
  for real-time signals is broken. http://b/5828899

  Too few TLS slots mean we can't allocate 128 pthread_key_t instances,
  which POSIX says should be the minimum.

  atexit(3) handlers registered by a shared library aren't called on
  dlclose(3); this only affects ARM. http://b/4998315