to spawn an lldb child command.  The test is not "correct" in that the '** Stop Hooks **'
message emitted by the Target implementation is invoked asynchronously and is using a separate:

    CommandReturnObject result;

command return object that what the driver passes to the normal command interpreter loop.
But it can help test our output serialization work.

I need to modify the test case later to maybe only test that "-o 'expr ptr'" option does indeed work.

llvm-svn: 130742

llvm-svn: 129880

This uses pexpect module to spawn a 'lldb' program and uses pseudo-TTY to talk to
the child application.

The test cases test setting breakpoints, adding a stop-hook with line range, and
verifies that when the inferior stops, the stop-hook will fire off when it is
within range and will not fire off when it is out of range.

llvm-svn: 127519