Merge branch 'bpf: Support ksym detection in light skeleton.'

Merge branch 'bpf: Support ksym detection in light skeleton.'

Alexei Starovoitov says:

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From: Alexei Starovoitov <ast@kernel.org>

v1->v2: update denylist on s390

Patch 1: Cleanup internal libbpf names.
Patch 2: Teach the verifier that rdonly_mem != NULL.
Patch 3: Fix gen_loader to support ksym detection.
Patch 4: Selftest and update denylist.
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Signed-off-by: Andrii Nakryiko <andrii@kernel.org>