Make bash use of fdescfs use optional, disabled by default, and forced off when

disabled.

This allows users to avoid mounting an extra FS that we don't enable by default.

Only display pkg-message with fdescfs instructions when option is enabled.

Submitted by:	swills
Differential Revision:	https://reviews.freebsd.org/D10394

shells/bash/Makefile

@@ -4,7 +4,7 @@
 PORTNAME=		bash
 PATCHLEVEL=		12
 PORTVERSION=		4.4.${PATCHLEVEL:S/^0//g}
-PORTREVISION?=		1
+PORTREVISION?=		2
 CATEGORIES=		shells
 MASTER_SITES=		GNU/${PORTNAME}
 DISTNAME=		${PORTNAME}-${PORTVERSION:R}
@@ -22,8 +22,9 @@ COMMENT=		GNU Project's Bourne Again SHell
 LICENSE=		GPLv3+
 LICENSE_FILE=		${WRKSRC}/COPYING
 
-OPTIONS_DEFINE=		COLONBREAKSWORDS HELP NLS STATIC SYSLOG DOCS
+OPTIONS_DEFINE=		COLONBREAKSWORDS FDESCFS HELP NLS STATIC SYSLOG DOCS
 COLONBREAKSWORDS_DESC=	Colons break words
+FDESCFS_DESC=		Enable use of /dev/fd
 HELP_DESC=		Enable builtin help
 
 OPTIONS_DEFAULT=	COLONBREAKSWORDS HELP
@@ -35,6 +36,9 @@ CPE_VENDOR=		gnu
 
 COLONBREAKSWORDS_EXTRA_PATCHES=	${PATCHDIR}/extrapatch-colonbreakswords
 
+FDESCFS_CONFIGURE_ENV_OFF=	bash_cv_dev_fd=absent
+FDESCFS_SUB_FILES=	pkg-message
+
 HELP_CONFIGURE_ENABLE=	help-builtin
 NLS_CONFIGURE_ENABLE=	nls
 NLS_USES=		gettext