Report the result of waitpid() a little more clearly as well as clearly logging the process status.

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@207698 91177308-0d34-0410-b5e6-96231b3b80d8
Allow for a task port to change when we exec. 

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@207699 91177308-0d34-0410-b5e6-96231b3b80d8
Sometimes when launching through a shell, we can run into cases where the /bin/sh or /usr/bin/arch can crash the process due to security measures. Now we correctly report when a process exited in the process of launching so we can show the reason why it crashed instead of just showing “initial process state wasn't stopped: exited”.

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@207700 91177308-0d34-0410-b5e6-96231b3b80d8