* java/lang/PosixProcess.java (exitValue): Implement here. Throw
	IllegalThreadStateException if process hasn't exited yet.
	* java/lang/natPosixProcess.cc (exitValue): Removed.
	(waitFor): Only check thread interrupted status if waitpid()
	returned an error. Use WIFEXITED and WEXITSTATUS to process process's
	exit value.

From-SVN: r45766