toolchain/56150: Tools do not build correctly on OpenBSD 6.9

[cjep%netbsd.org@localhost]

>Number:         56150
>Category:       toolchain
>Synopsis:       Tools do not build correctly on OpenBSD 6.9
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    toolchain-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu May 06 15:05:00 +0000 2021
>Originator:     Chris Pinnock
>Release:        NetBSD-current sources as of 6/5
>Organization:
>Environment:

OpenBSD luna 6.9 GENERIC.MP#473 amd64

>Description:
./build.sh (-U -m amd64) tools finishes successfully but 
./build.sh build fails as follows:

#    create  libgcc/__gcc_bcmp.d
CC=/home/cjep/netbsd-current/src/obj/tooldir.OpenBSD-6.9-amd64/bin/x86_64--netbsd-gcc /home/cjep/netbsd-current/src/obj/tooldir.OpenBSD-6.9-amd64/bin/nbmkdep -f __gcc_bcmp.d.tmp  --   -std=gnu99   --sysroot=/home/cjep/netbsd-current/src/obj/destdir.amd64 -I/home/cjep/netbsd-current/src/external/gpl3/gcc/lib/libgcc/libgcc -I/home/cjep/netbsd-current/src/external/gpl3/gcc/lib/libgcc/arch/x86_64 -I/home/cjep/netbsd-current/src/external/gpl3/gcc/usr.bin/gcc/arch/x86_64 -DIN_GCC -DIN_LIBGCC2 -I/home/cjep/netbsd-current/src/external/gpl3/gcc/dist/libgcc/../gcc/config/i386 -I/home/cjep/netbsd-current/src/external/gpl3/gcc/dist/libgcc -I/home/cjep/netbsd-current/src/external/gpl3/gcc/dist/libgcc/. -I/home/cjep/netbsd-current/src/external/gpl3/gcc/dist/libgcc/../gcc -I/home/cjep/netbsd-current/src/external/gpl3/gcc/dist/libgcc/../include -fpic -fbuilding-libgcc -fno-stack-protector -I/home/cjep/netbsd-current/src/external/gpl3/gcc/dist/gcc/config/i386 -I/home/cjep/netbsd-current/src/external/
 gpl3/gcc/dist/gcc/ginclude -I/home/cjep/netbsd-current/src/external/gpl3/gcc/dist/libgcc -I/home/cjep/netbsd-current/src/external/gpl3/gcc/dist/libgcc/config -I/home/cjep/netbsd-current/src/external/gpl3/gcc/dist/libgcc/config/i386 -I/home/cjep/netbsd-current/src/external/gpl3/gcc/dist/gcc -I/home/cjep/netbsd-current/src/external/gpl3/gcc/dist/include -I. -DHAVE_CC_TLS -I/home/cjep/netbsd-current/src/external/gpl3/gcc/usr.bin/backend/obj     __gcc_bcmp.c &&  mv -f __gcc_bcmp.d.tmp __gcc_bcmp.d
x86_64--netbsd-gcc: fatal error: '-fuse-linker-plugin', but liblto_plugin.so not found
compilation terminated.

On inspection the shared opject has been created with version numbers:
luna:~/netbsd-current/src/obj/tooldir.OpenBSD-6.9-amd64/libexec/gcc/x86_64--netbsd/10.3.0$ ls -l liblto*
liblto_plugin.la
liblto_plugin.so.0.0

suggesting an issue when building tools.

>How-To-Repeat:
1. Stock OpenBSD 6.9 installation
2. Grab latest current tar balls
3. ./build.sh -U -m amd64 build

>Fix:

>Unformatted:
 Host OS OpenBSD 6.9