i965/fs: Set force_uncompressed and force_sechalf on samplepos setup.
i965/fs: Set force_uncompressed and force_sechalf on samplepos setup.

gen8_fs_generator uses these to decide whether to set the execution size
to 8 or 16, so we incorrectly made both of these MOVs the full width in
SIMD16 shaders.  (It happened to work out on Gen4-7.)

Setting them should also help inform optimization passes what's really
going on, which could help avoid bugs.

Signed-off-by: Kenneth Graunke <bd2562f754ec92342f93f61c25d731e290a2ffa8@whitecape.org>
Reviewed-by: Matt Turner <789b315743a28dd066a4ba1459c35951c291d8a6@gmail.com>
Reviewed-by: Chris Forbes <5dcac483e7a6e31a5cbe89f38cc69dff8ee93dac@ijw.co.nz>
Cc: 59f39c0db42d4479a46b02d4d2bc11120e37bb44@lists.freedesktop.org

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