This patch consolidates the open Linux syscall implementation on
sysdeps/unix/sysv/linux/open{64}.c. The changes are:
1. Remove open{64} from auto-generation syscalls.list.
2. Add a new open{64}.c implementation. For architectures that
define __OFF_T_MATCHES_OFF64_T the default open64 will create
alias to required open symbols.
3. Use __NR_openat as default syscall for open{64}.
Checked on i686-linux-gnu, x86_64-linux-gnu, x86_64-linux-gnux32,
arch64-linux-gnu, arm-linux-gnueabihf, and powerpc64le-linux-gnu.
* sysdeps/unix/sysv/linux/generic/open.c: Remove file.
* sysdeps/unix/sysv/linux/generic/open64.c: Likewise.
* sysdeps/unix/sysv/linux/wordsize-64/open64.c: Likewise.
* sysdeps/unix/sysv/linux/open.c: New file.
* sysdeps/unix/sysv/linux/open64.c (__libc_open64): Use O_LARGEFILE
only for __OFF_T_MATCHES_OFF64_T and add alias to open if the case.
* sysdeps/unix/sysv/linux/wordsize-64/syscalls.list: Remove open
from auto-generated list.
