Fix the behavior when hand-calling a function times out on one thread,
but by the time we go to halt, it has already stopped by hitting the 
function end breakpoint.  That wasn't being shown to the threads so the
Function call thread plan didn't know its job was done.

<rdar://problem/16515785>


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@205803 91177308-0d34-0410-b5e6-96231b3b80d8