glsl: Use ir_var_temporary for compiler generated temporaries

These few places were using ir_var_auto for seemingly no reason.  The
names were not added to the symbol table.

No change Valgrind massif results for a trimmed apitrace of dota2.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
3 files changed