dEQP-GLES31.functional.texture.border_clamp.formats.bgra.* is broken under emugbgra

These dEQP tests get broken by mesa CL

mesa/mesa!6847 (merged)

first

Then it's good after

mesa/mesa!8119 (merged)

But then get broken again with

mesa/mesa!8664 (merged)

Now on ToT mesa, these 6 dEQP tests fails under virgl unless run with "VIRGL_DEBUG=noemubgra"

dEQP-GLES31.functional.texture.border_clamp.formats.bgra.nearest_size_pot
dEQP-GLES31.functional.texture.border_clamp.formats.bgra.nearest_size_npot
dEQP-GLES31.functional.texture.border_clamp.formats.bgra.linear_size_pot
dEQP-GLES31.functional.texture.border_clamp.formats.bgra.linear_size_npot
dEQP-GLES31.functional.texture.border_clamp.formats.bgra.gather_size_pot
dEQP-GLES31.functional.texture.border_clamp.formats.bgra.gather_size_npot