glsl: raise warning when using uninitialized variables

v2:
 * Take into account out varyings too (Timothy Arceri)
 * Fix style (Timothy Arceri)
 * Use a new ast_expression variable, instead of an
   ast_expression::hir new parameter (Timothy Arceri)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94129

Reviewed-by: Timothy Arceri <timothy.arceri@collabora.com>
1 file changed