Consolidate posix_fallocate{64} implementations

Consolidate posix_fallocate{64} implementations

This patch consolidates all the posix_fallocate{64} implementation for Linux
in only one (sysdeps/unix/sysv/linux/posix_fallocate{64}.c).  It also removes
the syscall from the auto-generation using assembly macros.

The macro SYSCALL_LL{64} is used to handle the offset argument along with
the new INTERNAL_SYSCALL_CALL macro to define correct argument count for
internal INTERNAL_SYSCALL call.

Tested on x86_64, i686, x32, aarch64, ppc64le, and armhf.

	* io/Makefile (tests): Add tst-posix_fallocate and
	tst-posix_fallocate64.
	* io/tst-posix_fallocate-common.c: New file.
	* io/tst-posix_fallocate.c: Likewise.
	* io/tst-posix_fallocate64.c: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n32/posix_fallocate.c: Remove
	file.
	* sysdeps/unix/sysv/linux/mips/mips64/n32/posix_fallocate64.c:
	Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n64/posix_fallocate.c: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n64/posix_fallocate64.c:
	Likewise.
	* sysdeps/unix/sysv/linux/wordsize-64/posix_fallocate.c: Likewise.
	* sysdeps/unix/sysv/linux/wordsize-64/posix_fallocate64.c: Likewise.
	* sysdeps/unix/sysv/linux/posix_fallocate.c (posix_fallocate): Use
	SYSCALL_LL to pass both offset and len arguments.
	* sysdeps/unix/sysv/linux/posix_fallocate64.c (posix_fallocate64):
	Likewise.
	* sysdeps/unix/sysv/linux/x86_64/syscalls.list (pwrite64): Add
	__libc_pwrite64 alias used by posix_fallocate64.