Loading certain sites in Firefox ESR causes the tab to crash, and on
occasion, the browser as a whole. A reliable cause of this is the Google
account login page, which this crash makes impossible to traverse.

I had to start the browser with MOZ_CRASHREPORTER_DISABLE=1 set in
the environment to disable BreakPad, or else I would not get useful
telemetry from the system logs.

The terminal output shows

    Illegal instruction

and syslog shows these entries:

    2023-08-27T02:31:20.899434-04:00 darkstar kernel: [  713.633343] traps: Isolated Web Co[2454] trap invalid opcode ip:b0af8174 sp:bff0c340 error:0 in libxul.so[ab957000+5c91000]
    2023-08-27T02:33:48.231483-04:00 darkstar kernel: [  860.962987] traps: Isolated Web Co[2843] trap invalid opcode ip:b0af8abc sp:bfcd35b0 error:0 in libxul.so[ab957000+5c91000]

This is on a Pentium M laptop running the i386 build of Debian bookworm.
CPU information:

    $ cat /proc/cpuinfo
    processor	: 0
    vendor_id	: GenuineIntel
    cpu family	: 6
    model	: 13
    model name	: Intel(R) Pentium(R) M processor 1.80GHz
    stepping	: 6
    microcode	: 0x17
    cpu MHz	: 800.000
    cache size	: 2048 KB
    physical id	: 0
    siblings	: 1
    core id	: 0
    cpu cores	: 1
    apicid	: 0
    initial apicid	: 0
    fdiv_bug	: no
    f00f_bug	: no
    coma_bug	: no
    fpu		: yes
    fpu_exception	: yes
    cpuid level	: 2
    wp		: yes
    flags	: fpu vme de pse tsc msr mce cx8 sep mtrr pge mca cmov clflush dts acpi mmx fxsr sse sse2 ss tm pbe bts cpuid est tm2 pti
    bugs	: cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit mmio_unknown
    bogomips	: 3588.46
    clflush size	: 64
    cache_alignment	: 64
    address sizes	: 36 bits physical, 32 bits virtual
    power management: