Comment 2 for bug 1563420

I've prepared a package with these changes, but I haven't been able to test it. I'm observing the following failure in both patched and unpatched builds, and also with the latest upstream trunk:

ubuntu@ubuntu:~/valgrind$ VALGRIND_LIB=$(pwd)/.in_place $(pwd)/coregrind/valgrind /bin/true
==31168== Memcheck, a memory error detector
==31168== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==31168== Using Valgrind-3.12.0.SVN and LibVEX; rerun with -h for copyright info
==31168== Command: /bin/true
==31168==
vex s390->IR: unimplemented insn: EC12 2021 1E59
==31168== valgrind: Unrecognised instruction at address 0x400b916.
==31168== at 0x400B916: _dl_new_object (dl-object.c:98)
==31168== by 0x400B8EB: _dl_new_object (dl-object.c:87)
==31168== Your program just tried to execute an instruction that Valgrind
==31168== did not recognise. There are two possible reasons for this.
==31168== 1. Your program has a bug and erroneously jumped to a non-code
==31168== location. If you are running Memcheck and you just saw a
==31168== warning about a bad jump, it's probably your program's fault.
==31168== 2. The instruction is legitimate but Valgrind doesn't handle it,
==31168== i.e. it's Valgrind's fault. If you think this is the case or
==31168== you are not sure, please let us know and we'll try to fix it.
==31168== Either way, Valgrind will now raise a SIGILL signal which will
==31168== probably kill your program.
==31168==
==31168== Process terminating with default action of signal 4 (SIGILL)
==31168== Illegal opcode at address 0x400B916
==31168== at 0x400B916: _dl_new_object (dl-object.c:98)
==31168== by 0x400B8EB: _dl_new_object (dl-object.c:87)
==31168==
==31168== HEAP SUMMARY:
==31168== in use at exit: 0 bytes in 0 blocks
==31168== total heap usage: 0 allocs, 0 frees, 0 bytes allocated
==31168==
==31168== All heap blocks were freed -- no leaks are possible
==31168==
==31168== For counts of detected and suppressed errors, rerun with: -v
==31168== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
Illegal instruction (core dumped)