bug#40737: Segfault in arm gcc7, thumb2 builroot, with arm patch

I'm still seeing segfaults on rasbian on an rpi3. Have not tried
buildroot yet.

That patch *did* fix a boatload of errors on arm, but this segfault is
an unrelated problem I think. Only happens on arm though.

Here is a way to reproduce:

In the test-suite/standalone dir:
while GUILE_JIT_THRESHOLD=0 make TESTS=test-language check-TESTS; do
:;done

And then:
../../meta/uninstalled-env ../../libtool --mode=execute gdb
../../libguile/guile core

Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x76f505cc in scm_is_string (x=0x0) at strings.h:293
293 return SCM_HAS_TYP7 (x, scm_tc7_string);
[Current thread is 1 (Thread 0x76fe6010 (LWP 21616))]
(gdb) bt
#0 0x76f505cc in scm_is_string (x=0x0) at strings.h:293
#1 scm_string_to_symbol (string=0x0) at symbols.c:361
#2 0x722df4cc in ?? ()
Backtrace stopped: previous frame identical to this frame (corrupt
stack?)

	-----------------------------------------From: "Ludovic Courtès" 
To: [email protected]
Cc: [email protected]
Sent: Wednesday June 17 2020 6:36:34PM
Subject: Re: bug#40737: Segfault in arm gcc7, thumb2 builroot, with
arm patch

Hi Dale,

 [email protected] skribis:

 > Here is a backtrace of running guile on a builtroot constructed
 system
 > for rpi3.
 > Thumb2 instructions: BR2_ARM_INSTRUCTIONS_THUMB2=y
 > Gcc 7.5: BR2_GCC_VERSION="7.5.0"
 > Glibc.
 >
 > Uses the patch from
 >