clang problem building wasi-compiler-rt on (arch)Linux

[Mark Davies <mark%ecs.vuw.ac.nz@localhost>]

Trying to build the latest wasi-compiler-rt with the latest clang on our 
ArchLinux systems is dying with:

   [...]
[ 99%] Building C object clang_rt.crtbegin-wasm32.o
fatal error: error in backend: .fini_array sections are unsupported
PLEASE submit a bug report to 
https://github.com/llvm/llvm-project/issues/ and include the crash 
backtrace, preprocessed source, and associated run script.
Stack dump:
0.      Program arguments: /usr/pkg/bin/clang -fcommon 
-Qunused-arguments -Wno-error=implicit-int -Wno-error=int-conversion 
-Wno-error=incompatible-pointer-types -D_FORTIFY_SOURCE=2 -Wl,-zrelro 
-O2 -fno-exceptions -O2 --target=wasm32-unknown-unknown -fno-lto 
-std=c11 -DCRT_HAS_INITFINI_ARRAY -DEH_USE_FRAME_REGISTRY -fPIC 
-Wno-pedantic 
--sysroot=/local/scratch/pkgsrc/lang/wasi-compiler-rt/work.debretts/.buildlink/wasi 
-o 
/local/scratch/pkgsrc/lang/wasi-compiler-rt/work.debretts/compiler-rt-17.0.6.src/cmake-pkgsrc-build/lib/wasi/clang_rt.crtbegin-wasm32.o 
-c 
/local/scratch/pkgsrc/lang/wasi-compiler-rt/work.debretts/compiler-rt-17.0.6.src/lib/builtins/crtbegin.c 
-Qunused-arguments
1.      <eof> parser at end of file
  [...]
clang: error: clang frontend command failed with exit code 70 (use -v to 
see invocation)
clang version 17.0.6
Target: wasm32-unknown-unknown
Thread model: posix
InstalledDir: /usr/pkg/bin
clang: note: diagnostic msg:
********************

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang: note: diagnostic msg: /tmp/crtbegin-43655d.c
clang: note: diagnostic msg: /tmp/crtbegin-43655d.sh
clang: note: diagnostic msg:


Any ideas what is going on here?

This built back when it was v16 and obviously is building on NetBSD.
And ArchLinux's package system seems to build the same version with
no obvious differences.

cheers
mark