The problem for x32 is the {INTERNAL,INLINE}_SYSCALL C macros explicit
cast the arguments to 'long int', thus passing as 32 bits arguments
that should be passed to 64 bits.
Previous x32 implementation uses the auto-generated syscalls from
assembly macros (syscalls.list), so the {INTERNAL,INLINE}_SYSCALL
macros are never used with 64 bit argument in x32 (which are
internally broken for this ILP).
To fix it I used a strategy similar to MIPS64n32 (although both
ABI differs for some syscalls on how top pass 64-bits arguments)
where argument types for kernel call are defined using GCC extension
'typeof' with a arithmetic operation. This allows 64-bits arguments
to be defined while 32-bits argument will still passed as 32-bits.
I also cleanup the {INLINE,INTERNAL}_SYSCALL definition by defining
'inline_syscallX' instead of constructing the argument passing using
macros (it adds some readability) and removed the ununsed
INTERNAL_SYSCALL_NCS_TYPES define (since the patch idea is exactly to
avoid requiric explicit types passing).