i965 new VS: Fix bugs in pre-GEN6 psiz/flags computation
i965 new VS: Fix bugs in pre-GEN6 psiz/flags computation

This patch corrects two errors in the computation of the psiz/flags
VUE slot on pre-GEN5 when using the new VS backend:

- The clip flags (which should be stored in the w component of the
  first VUE slot) were being accidentally duplicated in all other
  components of that VUE slot, causing partially clipped triangles to
  sometimes disappear completely.

- The OR instruction wasn't being stored in "inst", causing the
  BRW_PREDICATE_NORMAL flag to be applied to the wrong instruction.

This patch fixes regressions in clipping behavior when using shaders
on GEN4-5.

Reviewed-by: Kenneth Graunke <bd2562f754ec92342f93f61c25d731e290a2ffa8@whitecape.org>

dellis1972/glsl-optimizer,zeux/glsl-optimizer,mcanthony/glsl-optimizer,zeux/glsl-optimizer,dellis1972/glsl-optimizer,metora/MesaGLSLCompiler,zz85/glsl-optimizer,benaadams/glsl-optimizer,metora/MesaGLSLCompiler,benaadams/glsl-optimizer,bkaradzic/glsl-optimizer,djreep81/glsl-optimizer,dellis1972/glsl-optimizer,zeux/glsl-optimizer,zz85/glsl-optimizer,tokyovigilante/glsl-optimizer,mapbox/glsl-optimizer,zz85/glsl-optimizer,wolf96/glsl-optimizer,zz85/glsl-optimizer,mapbox/glsl-optimizer,mcanthony/glsl-optimizer,jbarczak/glsl-optimizer,bkaradzic/glsl-optimizer,bkaradzic/glsl-optimizer,mcanthony/glsl-optimizer,dellis1972/glsl-optimizer,zeux/glsl-optimizer,jbarczak/glsl-optimizer,tokyovigilante/glsl-optimizer,tokyovigilante/glsl-optimizer,mapbox/glsl-optimizer,bkaradzic/glsl-optimizer,tokyovigilante/glsl-optimizer,djreep81/glsl-optimizer,wolf96/glsl-optimizer,bkaradzic/glsl-optimizer,mapbox/glsl-optimizer,metora/MesaGLSLCompiler,jbarczak/glsl-optimizer,benaadams/glsl-optimizer,mcanthony/glsl-optimizer,jbarczak/glsl-optimizer,djreep81/glsl-optimizer,jbarczak/glsl-optimizer,wolf96/glsl-optimizer,zz85/glsl-optimizer,djreep81/glsl-optimizer,benaadams/glsl-optimizer,wolf96/glsl-optimizer,mcanthony/glsl-optimizer,tokyovigilante/glsl-optimizer,benaadams/glsl-optimizer,dellis1972/glsl-optimizer,wolf96/glsl-optimizer,mapbox/glsl-optimizer,zeux/glsl-optimizer,zz85/glsl-optimizer,benaadams/glsl-optimizer,djreep81/glsl-optimizer