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