Merge branch 'bpf-volatile-compare'

Merge branch 'bpf-volatile-compare'

Alexei Starovoitov says:

====================
bpf: volatile compare

From: Alexei Starovoitov <ast@kernel.org>

v2->v3:
Debugged profiler.c regression. It was caused by basic block layout.
Introduce bpf_cmp_likely() and bpf_cmp_unlikely() macros.
Debugged redundant <<=32, >>=32 with u32 variables. Added cast workaround.

v1->v2:
Fixed issues pointed out by Daniel, added more tests, attempted to convert profiler.c,
but barrier_var() wins vs bpf_cmp(). To be investigated.
Patches 1-4 are good to go, but 5 needs more work.
====================

Link: https://lore.kernel.org/r/20231226191148.48536-1-alexei.starovoitov@gmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>