Refresh the statepoint docs a bit

The documentation had gotten a bit stale.  The revised one are by no means perfect, but I tried to remove the obvious incorrect or misleading statements.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300782 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed