the lifetime of compound literals is the block in which they appear.
the temporary struct __timespec_kernel objects created as compound
literals no longer existed at the time their addresses were passed to
the kernel.
it's legal to call the __syscall functions with more arguments than
necessary, and the __syscall_cp cancel dummy impl. does just that.
thus we must insert the switch for all possible syscalls numbers
into all of the syscallN inline functions.
