Specifically, fix this error (which is covered in existing tests):
../src/compiler/glsl/glcpp/pp.c:198:28: runtime error: applying non-zero offset 1 to null pointer
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior ../src/compiler/glsl/glcpp/pp.c:198:28 in
Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9669>