i965/fs: Handle negating immediates on MADs when propagating saturates
MADs don't take immediate sources, but we allow them in the IR since it simplifies a lot of things. I neglected to consider that case. Fixes: 4009a9ea ("i965/fs: Allow saturate propagation to propagate negations into MADs.") Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=103616 Reported-and-Tested-by:Ruslan Kabatsayev <b7.10110111@gmail.com> Reviewed-by:
Ian Romanick <ian.d.romanick@intel.com>