clang/lld 4.0.0 arm64 link failure in sys/boot/efi/boot1 on arm64

[tech-lists]

hi toolchain@,

I'm trying to buildworld on a raspberrypi3 HardenedBSD-12 context.

FreeBSD clang version 4.0.0 (tags/RELEASE_400/final 297347) (based on
LLVM 4.0.0)
Target: aarch64-unknown-freebsd12.0
Thread model: posix
InstalledDir: /usr/bin

LLVM (http://llvm.org/):
LLVM version 4.0.0
Optimized build.
Default target: aarch64-unknown-freebsd12.0
Host CPU: (unknown)

It's failing in sys/boot/efi/boot1 with this sort of error:

/ldscript.arm64 -Wl,-Bsymbolic -shared -nostdlib -Wl,-z,relro -Wl,-z,now
-o boot1.sym.full boot1.o self_reloc.o start.o ufs_module.o  -lstand
/usr/bin/ld: error: /hd0/src/lib/libstand/printf.c:(.rodata+0x0): can't
create dynamic relocation R_AARCH64_ABS64 against local symbol in
readonly segment defined in /usr/lib/libstand.a(printf.o)
/usr/bin/ld: error: /hd0/src/lib/libstand/printf.c:(.rodata+0x8): can't
create dynamic relocation R_AARCH64_ABS64 against local symbol in
readonly segment defined in /usr/lib/libstand.a(printf.o)

I've refreshed to very latest sources but get the same error. Full
output is here:

http://www.zyxst.net/~bofh/rpi3/2017-04-29.buildworldfail.hbsd12-aarch64.txt

I note that a very similar error involving a different efi directory was
reported back in January:

http://freebsd.1045724.x6.nabble.com/clang-lld-4-0-0-arm64-link-failure-in-sys-boot-efi-loader-td6161866.html

...but no resolution/fix. Is there anything I can do?

many thanks,
-- 
J.