sched_ext: Sync common and compat headers from the scx repo

Sync cid.bpf.h, common.bpf.h, compat.bpf.h and compat.h with the scx repo at
c9b90b3ad3d0 ("scheds/include: Sync with kernel sched_ext/for

sched_ext: Sync common and compat headers from the scx repo

Sync cid.bpf.h, common.bpf.h, compat.bpf.h and compat.h with the scx repo at
c9b90b3ad3d0 ("scheds/include: Sync with kernel sched_ext/for-7.4
(c6fe97c34a1a)"), which accumulated the following since the last sync:

- cid.bpf.h grew the cmask helpers the cid-form schedulers use: fill, empty
and end tests, unchecked and word-level access, distribute picks over an
arena rotor indexed by cid, range set and clear, and three-operand and, or
and andnot that report whether the result is empty. Its word loops walk
with bpf_arena_for() and its bit helpers take the fetching atomics when
the loader's probe finds the JIT lowers them.

- The prolog probe's default now makes is_migration_disabled() over-report,
which errs toward local-only dispatch instead of crashing, and the
cid-form open macros repoint the probe at bpf_scx_reg_cid(), which
cid-form schedulers register through.

- scx_bpf_kick_cid() and scx_bpf_cidperf_set() changed their return types
without being renamed, so compat.bpf.h declares both flavors of each and
lets the kernel pick, the way scx_bpf_dsq_insert() is handled.

- A macro supplies scx_bpf_cid_topo()'s size argument from the output
buffer, TRAILING_OVERLAP() embeds a struct that ends in a flexible array
together with its storage, bpf_arena_for() walks a range in a form the
verifier converges on, and features.bpf.h carries the kernel feature bits
the loader probes before load. const-defs.h holds the per-architecture
cacheline size that cid.bpf.h aligns its rotor slots to.

scx_qmap already used the cmask helpers, and the three-operand forms of
cmask_and() and cmask_andnot() had not reached its copy of cid.bpf.h, so
tools/sched_ext no longer built against scx's headers. Its five calls take
the three-operand form now, with the copy-then-operate pairs folded into one
call each.

Signed-off-by: Tejun Heo <tj@kernel.org>

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