MFC r349548:

Build lib32 libl. The library is built from usr.bin/lex/lib. It would be
better to move this directory to lib/libl, but this requires more extensive
changes to Makefile.inc1. This simple fix can be MFCed quickly.

PR: 238874
Reviewed by: imp

MFC 337270: Install the 32-bit compat sanitizer libraries.

The lib32 build was already building the i386 version of
the clang sanitizers (libclang_rt) but they were not being
installed. This enables the installation.

MK_TOOLCHAIN=no was originally added to the install make
environment to disable includes so that NO_INCS could be
removed. The MK_TOOLCHAIN in bsd.incs.mk was subsequently
renamed to MK_INCLUDES, but bsd.lib.mk doesn't even include
bsd.incs.mk when LIBRARIES_ONLY is defined which the install
make environment for compat libs now defines. However,
setting MK_TOOLCHAIN=no forced MK_CLANG=no which disabled
libclang_rt during the install32 phase. Remove MK_TOOLCHAIN=no
since LIBRARIES_ONLY is now sufficient.

Since the libcompat environment overrides both LIBDIR and
SHLIBDIR, libclang_rt/Makefile.inc has to set both variables
to force the libraries to be installed to the location
expected by the compiler.

MFC r324143:

Adjust r322633 to only apply to libexec/rtld-elf, and not usr.bin/ldd,
when running build32/install32

This unbreaks installing usr.bin/ldd as ldd32 when NO_RTLD is defined.

MFC with: r322633

MFC r322633:

Honor NO_RTLD for rtld-elf, similar to what's done in libexec/Makefile, with
libexec/rtld-elf/... for MK_{LIB32,LIBSOFT}.

MFC r321684:

Don't use libc++ when cross-building for gcc arches

Since we imported clang 5.0.0, the version check in Makefile.inc1 which
checks whether to use libc++ fires even when the compiler for the target
architecture is gcc 4.2.1. This is because only X_COMPILER_VERSION is
checked. Also check X_COMPILER_TYPE, so it will only use libc++ when an
external gcc toolchain is used.

Reviewed by: emaste, rpokala
Differential Revision: https://reviews.freebsd.org/D11776

MFC r322170:

Follow-up to r321684 (Don't use libc++ when cross-building for gcc
arches), and handle two more cases where libc++ includes could be
incorrectly enabled, in case the host compiler is clang 5.0.0, and the
target (cross) compiler is gcc 4.2.1.

Noted by: bdrewery

MFC r312857: Use cross-NM (XNM) in compat32 build

An attempt to build mips64 using external toolchain failed as it tried
to use the host amd64 nm.

MFC r316586:

META_MODE: Fix build-tools still sometimes rebuilding during target build.

MFC r303274:

Don't disable binutils/elftoolchain bootstrapping with external compiler.

Approved by: re (kib)