runtime/mercury_goto.h:
    Replace a reference to "const struct MR_LabelLayout *"
    with "const MR_LabelLayout *". The old version was a bug, because

    - MR_LabelLayout is DEFINED as "struct MR_LabelLayout_Struct", and
    - there is NO STRUCT named just "MR_LabelLayout".

    It seems old versions of gcc accepted the code anyway, but with
    gcc 15, this bug led to the failure of no_refs_to_deleted_labels
    in tests/hard_coded.