It implements all the required syscall for the all Linux kABIS on
fstatat{64} instead of calling fxstatat{64}.
On non-LFS implementation, it handles 3 cases:
1. New kABIs which uses generic pre 64-bit time Linux ABI (csky and
nios): it issues __NR_fstat64 plus handle the overflow on st_ino,
st_size, or st_blocks.
2. Old KABIs with old non-LFS support (arm, i386, hppa, m68k,
microblaze, mips32, s390, sh, powerpc, and sparc32): it issues
__NR_fstatat64 and convert the result to struct stat.
3. 64-bit kABI outliers (mips64 and mips64-n32): it issues
__NR_newfstatat and convert the result to struct stat.
The generic LFS implementation handles multiple cases:
1. XSTAT_IS_XSTAT64 being 1:
1.1. 64-bit kABI (aarch64, ia64, powerpc64*, s390x, riscv64, and
x86_64): it issues __NR_newfstatat.
1.2. 64-bit kABI outlier (alpha): it issues __NR_fstatat64.
1.3. 64-bit kABI outlier where struct stat64 does not match kernel
one (sparc64): it issues __NR_fstatat64 and convert the result
to struct stat64.
1.4. 32-bit kABI with default 64-bit time_t (arc, riscv32): it
issues __NR_statx and convert the result to struct stat64.
2. Old ABIs with XSTAT_IS_XSTAT64 being 0:
2.1. All kABIs with non-LFS support (arm, csky, i386, hppa, m68k,
microblaze, nios2, sh, powerpc32, and sparc32): it issues
__NR_fstatat64.
2.2. 64-bit kABI outliers (mips64 and mips64-n32): it issues
__NR_newfstatat and convert the result to struct stat64.
It allows to remove all the hidden definitions from the {f,l}xstat{64}
(some are still kept because Hurd requires it).
Checked with a build for all affected ABIs. I also checked on x86_64,
i686, powerpc, powerpc64le, sparcv9, sparc64, s390, and s390x.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
