glsl: Convert ir_binop_vector_extract in the LHS to ir_triop_vector_insert
glsl: Convert ir_binop_vector_extract in the LHS to ir_triop_vector_insert

The ast_array_index code can't know whether to generate an
ir_binop_vector_extract or an ir_triop_vector_insert.  Instead it will
always generate ir_binop_vector_extract, and the LHS and RHS have to be
re-written.

v2: Convert tabs to spaces.  Suggested by Eric.

Signed-off-by: Ian Romanick <2b237cafb16dc45038e85df6c85e74e6d899eba9@intel.com>
Reviewed-by: Eric Anholt <96f164ad4d9b2b0dacf8ebee2bb1eeb3aa69adf1@anholt.net>
Reviewed-by: Kenneth Graunke <bd2562f754ec92342f93f61c25d731e290a2ffa8@whitecape.org>

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