Switch local launching of debugserver over to always use a FIFO in order to handshake with the launched debugserver.

This helps ensure that the launched debugserver is ready and listening for a connection. Prior to this we had a race condition.

Consolidate the launching of debugserver into a single place: a static function in GDBRemoteCommunication.



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@196401 91177308-0d34-0410-b5e6-96231b3b80d8
Remove log line that was left in accidentally.



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@196403 91177308-0d34-0410-b5e6-96231b3b80d8
Enable POSIX_SPAWN_CLOEXEC_DEFAULT (a darwin specific flag) when available when using posix_spawn to spawn processes to close all file handles.



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@196404 91177308-0d34-0410-b5e6-96231b3b80d8
Allow the hostname to be specified when asking a platform to launch another debugserver in case you want to change it.

The GDB server remote platform how has the debugserver that are launched on iOS devices to use localhost due to the use of a USB mux.



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@196405 91177308-0d34-0410-b5e6-96231b3b80d8