[Mesa-dev] formats fixes for glcts pixel store tests

[Dave Airlie]

The glcts has two tests

GL33-CTS.gtf32.GL3Tests.packed_pixels.packed_pixels
and
GL33-CTS.gtf32.GL3Tests.packed_pixels.packed_pixels_pixelstore

that try all the valid combinations of things at TexImage, GetTexImage
and ReadPixels.

This series of patches is a first round of fixes:

a) SwapBytes handling was broken in the presence of (UN)PACK_ROW_LENGTH
with a 1-byte format/type combo,
b) GetTexImage on a compressed format has no swap bytes handling
c) format/type combinations for integer were missing internal formats
to handle conversion to/from them. two patches add the internal formats
for all cases these tests throw at us.

This series alone doesn't completely fix the test on my cayman gpu,
the other patches I've got to fix the remaining cases all involve
disabling the mesa/st fast paths or fastpaths in readpix or
texcompress_s3tc. I'll try and narrow those down to real fixes
as well.

Dave.