zink: be more consistent about applying module hash for gfx pipeline

this was a little spaghetti-ish: the module hash was sometimes being applied
during module update, sometimes in draw during program create, and then also
it was removed when a shader unbind would cause the program to no longer be reachable

now things are more consistent:
* keep removing module hash when program becomes unreachable
* only apply module hash in draw during updates there

cc: mesa-stable

Reviewed-by: Dave Airlie <airlied@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13727>

src/gallium/drivers/zink/zink_draw.cpp

@@ -207,7 +207,11 @@ update_gfx_program(struct zink_context *ctx)
       ctx->gfx_pipeline_state.final_hash ^= ctx->curr_program->last_variant_hash;
       ctx->gfx_dirty = false;
    } else if (ctx->dirty_shader_stages & bits) {
+      /* remove old hash */
+      ctx->gfx_pipeline_state.final_hash ^= ctx->curr_program->last_variant_hash;
       zink_update_gfx_program(ctx, ctx->curr_program);
+      /* apply new hash */
+      ctx->gfx_pipeline_state.final_hash ^= ctx->curr_program->last_variant_hash;
    }
    ctx->dirty_shader_stages &= ~bits;
 }

src/gallium/drivers/zink/zink_program.c

@@ -179,9 +179,6 @@ update_gfx_shader_modules(struct zink_context *ctx,
    }
 
    if (hash_changed && state) {
-      if (!first && likely(state->pipeline)) //avoid on first hash
-         state->final_hash ^= prog->last_variant_hash;
-
       if (default_variants && !first)
          prog->last_variant_hash = prog->default_variant_hash;
       else {
@@ -192,7 +189,6 @@ update_gfx_shader_modules(struct zink_context *ctx,
          }
       }
 
-      state->final_hash ^= prog->last_variant_hash;
       state->modules_changed = true;
    }
 }