This moves the definition of miPointerRec from mipointrst.h to
mipointer.c so that it is no longer visible in the API, allowing it to
be changed while the API/ABI is frozen.
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Signed-off-by: Keith Packard <keithp@keithp.com>