re PR libgcj/12231 ([win32] Console applications spawned via Runtime.exec( ) in a GUI application flash console window)

	PR libgcj/12231
	* java/lang/Win32Process.java (hasExited) Changed from
	public to private.
	(startProcess): Likewise.
	(cleanup): Likewise.
	* java/lang/natWin32Process.cc (cleanup) Don't close
	input, output and error streams.
	(ChildProcessPipe): New helper class.
	(startProcess): Refactored to use ChildProcessPipe.
	Use CREATE_NO_WINDOW when launching child process.

From-SVN: r73326