Define wordsize.h macros everywhere

Define wordsize.h macros everywhere

	* bits/wordsize.h: Add documentation.
	* sysdeps/aarch64/bits/wordsize.h : New file
	* sysdeps/generic/stdint.h (PTRDIFF_MIN, PTRDIFF_MAX): Update
	definitions.
	(SIZE_MAX): Change ifdef to if in __WORDSIZE32_SIZE_ULONG check.
	* sysdeps/gnu/bits/utmp.h (__WORDSIZE_TIME64_COMPAT32): Check
	with #if instead of #ifdef.
	* sysdeps/gnu/bits/utmpx.h (__WORDSIZE_TIME64_COMPAT32): Ditto.
	* sysdeps/mips/bits/wordsize.h (__WORDSIZE32_SIZE_ULONG,
	__WORDSIZE32_PTRDIFF_LONG, __WORDSIZE_TIME64_COMPAT32):
	Add or change defines.
	* sysdeps/powerpc/powerpc32/bits/wordsize.h: Likewise.
	* sysdeps/powerpc/powerpc64/bits/wordsize.h: Likewise.
	* sysdeps/s390/s390-32/bits/wordsize.h: Likewise.
	* sysdeps/s390/s390-64/bits/wordsize.h: Likewise.
	* sysdeps/sparc/sparc32/bits/wordsize.h: Likewise.
	* sysdeps/sparc/sparc64/bits/wordsize.h: Likewise.
	* sysdeps/tile/tilegx/bits/wordsize.h: Likewise.
	* sysdeps/tile/tilepro/bits/wordsize.h: Likewise.
	* sysdeps/unix/sysv/linux/alpha/bits/wordsize.h: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/bits/wordsize.h: Likewise.
	* sysdeps/unix/sysv/linux/sparc/bits/wordsize.h: Likewise.
	* sysdeps/wordsize-32/bits/wordsize.h: Likewise.
	* sysdeps/wordsize-64/bits/wordsize.h: Likewise.
	* sysdeps/x86/bits/wordsize.h: Likewise.