Fixes hang at the syscall ppoll_time64 by handling it same as ppoll. The former is the year-2038-safe variant of the latter, that allows a wider field for timestamp, as the year 2038 will see a unix timestamp greater than 2^31.
Adds new syscalls up to Linux kernel 5.10.46.
Adds a warning for new syscalls other than ppoll_time64 that are not handled yet and have a similarly named variant that needs special handling. E.g. SYS_clone has special handling, so added a warning for SYS_clone3.
Also upgrades Ubuntu version for the x86-32 bit GA CI to 20.04.
Issue: #5131 (closed) Fixes: #4953 (closed)