glsl: Drop do_common_optimization's max_unroll_iterations parameter.

Now that we pass in gl_shader_compiler_options, it makes sense to just
use options->MaxUnrollIterations, rather than passing a separate
parameter.

Half of the invocations already passed options->MaxUnrollIterations,
while the other half passed in a hardcoded value of 32.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>

src/glsl/ir_optimization.h

@@ -66,7 +66,6 @@ enum lower_packing_builtins_op {
 
 bool do_common_optimization(exec_list *ir, bool linked,
 			    bool uniform_locations_assigned,
-			    unsigned max_unroll_iterations,
                             const struct gl_shader_compiler_options *options,
                             bool native_integers);