Emma Anholt authored Feb 01, 2016 and Adam Jackson committed Mar 10, 2016

There was only a pretty special case that could have even worked --
you've got a GLES2 renderer, you've got a SHM pixmap, it's 1555 (not
the usual 565 for 16-bit), and you're little endian (BE was broken,
since GL's 5_5_5_1 picks the 1 bit from the lowest bit of the short,
and on BE we weren't doing the conversion path that swaps around the
channels).  This is just not worth the complexity.

Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Eric Anholt <eric@anholt.net>