Do not build lint(1) by default on stable-11, add WITH_LINT to enable

building it.

lint(1) is required on the host build system to build lint(1) libraries, and
it is no longer available on FreeBSD 12. This prevents using a 12 or later
host to build an 11 or earlier system, which causes problems for building
jails and using poudriere. The problem could be fixed by treating lint as a
bootstrap tool when building on 12+, but that just adds complexity and build
time to build a broken tool that virtually nobody uses anymore.

This is a direct commit to 11-stable because lint no longer exists in later
branches.

PR:		223892
Relnotes:	yes
Differential Revision:	https://reviews.freebsd.org/D13799

UPDATING

@@ -16,6 +16,12 @@ from older versions of FreeBSD, try WITHOUT_CLANG and WITH_GCC to bootstrap to
 the tip of head, and then rebuild without this option. The bootstrap process
 from older version of current across the gcc/clang cutover is a bit fragile.
 
+20180108:
+	lint(1) binaries and library are no longer built by default.  To
+	enable building them, define WITH_LINT in src.conf.  If you are using
+	a FreeBSD 12 or later system to build 11-stable, you may need to
+	install a lint(1) binary to use WITH_LINT.
+
 20171003:
 	When building multiple kernels using KERNCONF, non-existent KERNCONF
 	files will produce an error and buildkernel will fail. Previously

share/man/man5/src.conf.5

@@ -1,6 +1,6 @@
 .\" DO NOT EDIT-- this file is generated by tools/build/options/makeman.
 .\" $FreeBSD$
-.Dd September 7, 2017
+.Dd January 8, 2018
 .Dt SRC.CONF 5
 .Os
 .Sh NAME
@@ -927,6 +927,8 @@ Set to not build the
 .Nm libthr
 (1:1 threading)
 library.
+.It Va WITH_LINT
+Set to build the lint binaries and library.
 .It Va WITHOUT_LLD
 Set to not build LLVM's lld linker.
 .Pp

share/mk/src.opts.mk

@@ -187,6 +187,7 @@ __DEFAULT_NO_OPTIONS = \
     EISA \
     HESIOD \
     LIBSOFT \
+    LINT \
     NAND \
     OFED \
     OPENLDAP \

usr.bin/Makefile

@@ -286,7 +286,7 @@ SUBDIR.${MK_TOOLCHAIN}+=	readelf
 SUBDIR.${MK_TOOLCHAIN}+=	rpcgen
 SUBDIR.${MK_TOOLCHAIN}+=	unifdef
 SUBDIR.${MK_TOOLCHAIN}+=	size
-.if ${MACHINE_ARCH} != "aarch64" # ARM64TODO xlint does not build
+.if ${MK_LINT} != "no" && ${MACHINE_ARCH} != "aarch64" # ARM64TODO xlint does not build
 SUBDIR.${MK_TOOLCHAIN}+=	xlint
 .endif
 SUBDIR.${MK_TOOLCHAIN}+=	xstr