Merge branch 'allow-fixed-offsets-for-ptr_to_ctx'

Kumar Kartikeya Dwivedi says:

====================
Allow fixed offsets for PTR_TO_CTX

Enable pointer modification with constant offsets accumulated in the
register for PTR_TO_CTX for programs where it won't be rewritten. See
patches for details.
====================

Link: https://patch.msgid.link/20260227005725.1247305-1-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>