Added gdb-remote tests for q{f,s}ThreadInfo.

The First test verifies that qThreadInfo queries work for stub-launched processes.

The second test verifies that $qC after stub-launched inferior returns the same
thread as the qThreadInfo queries.


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@209314 91177308-0d34-0410-b5e6-96231b3b80d8