Defines starting with `p' in kern

• PF_NOSTOP kern/tty_pty.c:95
• PF_PKT kern/tty_pty.c:92
• PF_RCOLL kern/tty_pty.c:90
• PF_REMOTE kern/tty_pty.c:94
• PF_STOPPED kern/tty_pty.c:93
• PF_UCNTL kern/tty_pty.c:96
• PF_WCOLL kern/tty_pty.c:91
• PIPSIZ kern/uipc_usrreq.c:307
• PPQ kern/kern_synch.c:196