lima: fix ppir spill stack allocation

The previous spill stack was fixed and too small, and caused instability
in programs requiring spilling for roughly more than one value.
This patch adds a dynamic calculation of the buffer size based on stack
utilization and switches it to a separate allocation at flush time that
will fit the shader that requires the largest buffer.

Signed-off-by: Erico Nunes <nunes.erico@gmail.com>
Reviewed-by: Vasily Khoruzhick <anarsoul@gmail.com>
Reviewed-by: Qiang Yu <yuq825@gmail.com>

src/gallium/drivers/lima/lima_program.c

@@ -303,6 +303,8 @@ lima_update_fs_state(struct lima_context *ctx)
       fs->shader = NULL;
    }
 
+   ctx->pp_max_stack_size = MAX2(ctx->pp_max_stack_size, ctx->fs->stack_size);
+
    return true;
 }