IssueTracker

cros debug currently only has support for lldb, but simple extension points exist to add support for gdb. The basic task involves:

• Add a new subclass of Debugger, called GNUDebugger, to chromite/lib/debugger.py.
• implement the required methods for the base Debugger class in GNUDebugger.
• Add a check in the _RunLocal() and _RunRemote() methods in chromite/cli/cros/cros_debug.py when self.debug_server is set. Initialize the correct Debugger subclass according to the value of the --debugger CLI flag.
• Finish any additional cleanup or necessary gating of LLDB/GDB specific code. This hopefully should be straightforward, as most of the LLDB-specific code is contained within private methods in the LLVMDebugger class.
• Update help text and documentation, including the ChromiumOS Developer Guide.