DARWIN branch. A big ugly DARWIN/trunk sync commit, mostly to do with
changing the representation of SysRes and vki_sigset_t. Functionality of
the trunk shouldn't be changed by it.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@9876
Get rid of VG_(sigtimedwait) and replace it a simpler version,
VG_(sigtimedwait_zero), which polls for signals and returns
immediately. AIX doesn't have a sigtimedwait syscall, so in that case
try and implement VG_(sigtimedwait_zero) using various other signal
syscalls.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@6259
