Remove the debugserver "--open-connection" option and obey the hostname that...

Remove the debugserver "--open-connection" option and obey the hostname that is passed into debugserver.

you can now specify:

debugserver host:port
debugserver port
debugserver /path/to/file

When "host" is specified, we will only accept connections from that host. If host is not specified, we default to "localhost".

llvm-svn: 183457