native_handle_t support.

- writeEmbeddedNativeHandle to write a native_handle_t*
  embedded inside a buffer.
- Factored out writeEmbeddedBuffer to make clear the buffer
  is pointed to from inside another buffer.
- readBuffer()/readEmbeddedBuffer()/readEmbeddedNativeHandle()
- Added writeNativeHandleNoDup()/readNativeHandleNoDup() to
  avoid copying file descriptors around if the caller doesn't
  need it.
- Moved the binder header modifications inside libhwbinder
  for now, until we can get them upstreamed and pulled down
  to bionic's uapi headers again.

Change-Id: I3a2c44732f5dc9ed92363552b42aa3ff55a06a8d
3 files changed