i965: Fix bitcast operations with negate (ceil)

i965: Fix bitcast operations with negate (ceil)

Commit 0ae9ca12a8 put source modifiers out of the bitcast operations
by adding a MOV operation that would handle them separately. It missed
the case of ceil though: the implementation negates both its source and
destination operands. The source operand will be used for RNDD, which
we can handle normally, but we need to fix the modifier for the
negated result.

v2:
  - RNDD can handle the source modifier so no need to put that one
    in a separate MOV.

Fixes the following 42 dEQP tests:
dEQP-GLES3.functional.shaders.builtin_functions.common.ceil.*_vertex
dEQP-GLES3.functional.shaders.builtin_functions.common.ceil.*_fragment
dEQP-GLES3.functional.shaders.builtin_functions.precision.ceil._*vertex.*
dEQP-GLES3.functional.shaders.builtin_functions.precision.ceil._*fragment.*

Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com>