Bug 396220

Hi, I am trying to run Valgrind on SPEC CPU benchmark, and encountered the following error:

Essentially, Valgrind aborted with the following error:

vex x86->IR: unhandled instruction bytes: 0xC4 0xE2 0x41 0xF7

I'd be happy to check a patch when available to confirm a fix.

1530817135.71: ==27439== Nulgrind, the minimal Valgrind tool
1530817135.71: ==27439== Copyright (C) 2002-2017, and GNU GPL'd, by Nicholas Nethercote.
1530817135.71: ==27439== Using Valgrind-3.13.0 and LibVEX; rerun with -h for copyright info
1530817135.71: ==27439== Command: ../run_base_refrate_mytest-m32.0003/perlbench_r_base.mytest-m32 -I./lib checkspam.pl 2500 5 25 11 150 1 1 1 1
1530817135.71: ==27439==
1530817135.71: vex x86->IR: unhandled instruction bytes: 0xC4 0xE2 0x41 0xF7
1530817135.71: ==27439== valgrind: Unrecognised instruction at address 0x81521dd.
1530817135.71: ==27439==    at 0x81521DD: Perl_sv_upgrade (sv.c:1522)
1530817135.71: ==27439==    by 0x815676F: Perl_sv_setpvn (sv.c:4927)
1530817135.71: ==27439==    by 0x81577F7: Perl_newSVpvn (sv.c:9202)
1530817135.71: ==27439==    by 0x80A756B: perl_construct (perl.c:249)
1530817135.71: ==27439==    by 0x804ADDD: main (perlmain.c:114)
1530817135.71: ==27439== Your program just tried to execute an instruction that Valgrind
1530817135.71: ==27439== did not recognise.  There are two possible reasons for this.
1530817135.71: ==27439== 1. Your program has a bug and erroneously jumped to a non-code
1530817135.71: ==27439==    location.  If you are running Memcheck and you just saw a
1530817135.71: ==27439==    warning about a bad jump, it's probably your program's fault.
1530817135.71: ==27439== 2. The instruction is legitimate but Valgrind doesn't handle it,
1530817135.71: ==27439==    i.e. it's Valgrind's fault.  If you think this is the case or
1530817135.71: ==27439==    you are not sure, please let us know and we'll try to fix it.
1530817135.71: ==27439== Either way, Valgrind will now raise a SIGILL signal which will
1530817135.71: ==27439== probably kill your program.
1530817135.71: ==27439==
1530817135.71: ==27439== Process terminating with default action of signal 4 (SIGILL)
1530817135.71: ==27439==  Illegal opcode at address 0x81521DD
1530817135.71: ==27439==    at 0x81521DD: Perl_sv_upgrade (sv.c:1522)
1530817135.71: ==27439==    by 0x815676F: Perl_sv_setpvn (sv.c:4927)
1530817135.71: ==27439==    by 0x81577F7: Perl_newSVpvn (sv.c:9202)
1530817135.71: ==27439==    by 0x80A756B: perl_construct (perl.c:249)
1530817135.71: ==27439==    by 0x804ADDD: main (perlmain.c:114)