gcc/ChangeLog:

    * rtl.h (*rtx_equal_p_callback_function):
    Change return type from int to bool.
    (rtx_equal_p): Ditto.
    (*hash_rtx_callback_function): Ditto.
    * rtl.cc (rtx_equal_p): Change return type from int to bool
    and adjust function body accordingly.
    * early-remat.cc (scratch_equal): Ditto.
    * sel-sched-ir.cc (skip_unspecs_callback): Ditto.
    (hash_with_unspec_callback): Ditto.

Bootstrapped and regression tested on x86_64-linux-gnu {,-m32}.

Uros.