PowerPC64 ELFv2 support
	* src/powerpc/ffitarget.h: Import from upstream.
	* src/powerpc/ffi.c: Likewise.
	* src/powerpc/linux64.S: Likewise.
	* src/powerpc/linux64_closure.S: Likewise.
	* doc/libffi.texi: Likewise.
	* testsuite/libffi.call/cls_double_va.c: Likewise.
	* testsuite/libffi.call/cls_longdouble_va.c: Likewise.

From-SVN: r204917