PowerPC LE ABI tests

http://sourceware.org/ml/libc-alpha/2013-08/msg00096.html

This adds ABI tests for powerpc64le.

	* Makerules (abilist): Define and use var in abilist rules.
	* sysdeps/unix/sysv/linux/powerpc/Makefile (abilist): Define.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/nptl/ld-le.abilist,
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/nptl/libBrokenLocale-le.abilist,
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/nptl/libanl-le.abilist,
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/nptl/libc-le.abilist,
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/nptl/libcrypt-le.abilist,
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/nptl/libdl-le.abilist,
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/nptl/libm-le.abilist,
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/nptl/libnsl-le.abilist,
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/nptl/libpthread-le.abilist,
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/nptl/libresolv-le.abilist,
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/nptl/librt-le.abilist,
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/nptl/libthread_db-le.abilist,
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/nptl/libutil-le.abilist:
	New files.