[gjs/mcatanzaro/#336] Fix build on 32-bit architectures

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 843b729c6c4c86084af6a681a5f998ef9581de11
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Mon Aug 3 16:15:31 2020 -0500

    Fix build on 32-bit architectures
    
    Turns out GType is defined differently in C++ than in C:
    
     /**
      * GType:
      *
      * A numerical value which represents the unique identifier of a registered
      * type.
      */
     #if     GLIB_SIZEOF_SIZE_T != GLIB_SIZEOF_LONG || !defined __cplusplus
     typedef gsize                           GType;
     #else   /* for historic reasons, C++ links against gulong GTypes */
     typedef gulong                          GType;
     #endif
    
    Fix suggested by Philip Chimento. Special credit to Jordan for teaching
    me how to do a 32-bit build with buildstream!
    
    Fixes #336

 gi/arg-inl.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/gi/arg-inl.h b/gi/arg-inl.h
index 7a109ef4..087c8314 100644
--- a/gi/arg-inl.h
+++ b/gi/arg-inl.h
@@ -113,7 +113,7 @@ GJS_USE inline decltype(auto) gjs_arg_member<char32_t>(GIArgument* arg) {
 template <>
 GJS_USE inline decltype(auto) gjs_arg_member<GType, GI_TYPE_TAG_GTYPE>(
     GIArgument* arg) {
-    return gjs_arg_member(arg, &GIArgument::v_size);
+    return gjs_arg_member(arg, &GIArgument::v_ulong);
 }
 
 template <>