mesa: Convert colors if span ChanType and renderbuffer data type don't match
This is a partial revert of
f9874fe. It turns out that the types
don't always match. Specifically, this can happen when doing
glCopyPixels from a float FBO to a RGBA8 FBO.
NOTE: This is a candidate for the 8.0 branch.
Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=45429
Reviewed-by: Brian Paul <brianp@vmware.com>
(cherry picked from commit
660ed923ded3552e023ef8c3dd9f92e6792f1bd2)