Fix __smp_processor_id call for older kernels

test_update_config.sh: Add options such as --prepare

Fix egrep/fgrep calls

compat: Add netif_is_bridge_port for v4.4

Build compatibility with v6.4 (register_sysctl_paths)

Fix ipv4 options parsing and bit numbering

Fix possible out-of-bounds read in tcp_options fix

TCP Option 0 should participate in bitmask too

tcp options: fix possible shift-out-of-bounds

compat: Fix __has_attribute usage

nat_events: add expect callback

fix building on old kernels

Fix preemptive enabled warning

gen_compat_def: Catch 'dereferencing pointer to incomplete type'

Fix build on v5.15 (ct_event)