Fix tool.drcacheoff.rseq test regression

Migrating the AArch64 Jenkins CI to an Ampere Altera machine caused a regression in the tool.drcacheoff.rseq test:

*** postcmd failed (1): ERROR: Usage error: Unknown option: -test_mode

added Component-Tests OpSys-AArch64 labels

mentioned in issue #2417

The usage error above has been fixed by #4929 but the test now fails with failed to match expected output.

mentioned in merge request !4929 (merged)

mentioned in merge request !4981 (closed)

I believe GA CI Linux is hitting this same failure on Ubuntu 20.04 in release x86-64, and this is blocking our upgrade.

#4953 (closed) is the issue covering the upgrade

assigned to @derekbruening

It looks like it's just not passing -test_mode in release and that's why it doesn't print that it passed the invariants. I think the only reason is I was using assert(), but no more after PR #5077.

Xref where I was going to add a -simulator_type=invariant_checker for #5076 (closed). But here we want to run two simulators at once: so leave the -test_mode for that and just enable for release build? Slight extra overhead to check for the flag in analyzer_multi but should be fine.

mentioned in merge request !5099 (merged)

closed