glsl_type: Add packed to structure type comparison for hash map

Fixes: 659f333b3a4ff "glsl: add packed for struct types"
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6767>
diff --git a/src/compiler/glsl_types.cpp b/src/compiler/glsl_types.cpp
index 2a77b07..e160a47 100644
--- a/src/compiler/glsl_types.cpp
+++ b/src/compiler/glsl_types.cpp
@@ -1143,6 +1143,9 @@
    if (this->explicit_alignment != b->explicit_alignment)
       return false;
 
+   if (this->packed != b->packed)
+      return false;
+
    /* From the GLSL 4.20 specification (Sec 4.2):
     *
     *     "Structures must have the same name, sequence of type names, and