Fix typo in syswrap ppoll param, equate ppoll and poll for memcheck testcase.

ppoll argument is called ufds like the poll argument.
Newer architectures (aarch64) implement poll by calling ppoll directly.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14370 a5019735-40e9-0310-863c-91ae7b9d1cf9
none/tests/Makefile.am (DIST_SUBDIRS): Add arm64.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14371 a5019735-40e9-0310-863c-91ae7b9d1cf9
Add configure check for 32 bit build support on arm64-linux.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14373 a5019735-40e9-0310-863c-91ae7b9d1cf9