* fork-child.c: Don't include frame.h. Include terminal.h.

	* fork-child.c: Don't include frame.h.  Include terminal.h.
	(fork_inferior): Call new_tty_postfork after forking adn adding
	the child to the inferior list.
	* inferior.h (new_tty_prefork, gdb_has_a_terminal): Don't declare
	here.
	* inflow.c (struct terminal_info): Remove const qualifier from
	`run_terminal' field.
	(inferior_thisrun_terminal): Tweak comment.
	(inflow_inferior_exit): Release the `run_terminal' field.
	(copy_terminal_info): New function.
	(new_tty_postfork): New function.
	* terminal.h (new_tty_prefork, new_tty, new_tty_postfork,
	(copy_terminal_info, gdb_has_a_terminal, gdb_setpgid): Declare.
	* inf-ptrace.c: Include terminal.h.
	(inf_ptrace_follow_fork): Copy the parent's terminal info to the
	child.
	* linux-nat.c: Include terminal.h.
	(linux_child_follow_fork): Copy the parent's terminal info to the
	child.
	* inf-ttrace.c: Include terminal.h.
	(inf_ttrace_follow_fork): Copy the parent's terminal info to the
	child.