linux(4): Allow musl brand to use FUTEX_REQUEUE op.
Initial patch from submitter was adapted by me to prevent unconditional
FUTEX_REQUEUE use.
PR: 255947
Submitted by: Philippe Michaud-Boudreault
Differential Revision: https://reviews.freebsd.org/D30332
(cherry picked from commit cf8d74e3fe63da7359d6ca7e0b4b57c5684c2845)