Bug#892828: dwz internal error: dwz.c:9253: recompute_abbrevs: Assertion `off == cu_size' failed

[Matthias Klose <doko@debian.org>]

Package: dwz
Version: 0.12-2
Severity: important
Tags: sid buster

seen when building gcc-snapshot (r258456) on arm64:

dwz: dwz.c:9253: recompute_abbrevs: Assertion `off == cu_size' failed.

Program received signal SIGABRT, Aborted.
---Type <return> to continue, or q <return> to quit---
__GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51
51      ../sysdeps/unix/sysv/linux/raise.c: No such file or directory.
(gdb) bt
#0  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51
#1  0x0000ffffb7e6e9a4 in __GI_abort () at abort.c:79
#2  0x0000ffffb7e66b44 in __assert_fail_base (fmt=0xffffb7f63498 "%s%s%s:%u:
%s%sAssertion `%s' failed.\n%n",
    assertion=assertion@entry=0xaaaaaaaca388 "off == cu_size",
file=file@entry=0xaaaaaaac8d20 "dwz.c",
    line=line@entry=9253, function=function@entry=0xaaaaaaac8c40
"recompute_abbrevs") at assert.c:92
#3  0x0000ffffb7e66bc4 in __GI___assert_fail (assertion=0xaaaaaaaca388 "off ==
cu_size", file=0xaaaaaaac8d20 "dwz.c",
    line=9253, function=0xaaaaaaac8c40 "recompute_abbrevs") at assert.c:101
#4  0x0000aaaaaaac01b8 in ?? ()
#5  0x0000aaaab2fd8128 in ?? ()
Backtrace stopped: previous frame inner to this frame (corrupt stack?)
(gdb)

dwz -q -- <file>

where the command succeeds for cc1 and cc1obj, and fails with cc1plus and
cc1objplus, and succeeds for other languages.

test files at https://people.debian.org/~doko/tmp/tst-dwz.tar.xz

gcc configured with

         --enable-languages=c,ada,c++,go,fortran,objc,obj-c++
         --prefix=/usr/lib/gcc-snapshot
         --with-gcc-major-version-only
         --program-prefix=
         --enable-shared
         --enable-linker-build-id
         --disable-nls
         --with-sysroot=/
         --enable-clocale=gnu
         --enable-libstdcxx-debug
         --enable-libstdcxx-time=yes
         --with-default-libstdcxx-abi=new
         --enable-gnu-unique-object
         --disable-libquadmath
         --disable-libquadmath-support
         --enable-plugin
         --with-system-zlib
         --enable-multiarch
         --enable-fix-cortex-a53-843419
         --disable-werror
         --enable-checking=yes
         --build=aarch64-linux-gnu
         --host=aarch64-linux-gnu
         --target=aarch64-linux-gnu