AArch64 linux.thread-reset fails on non-SVE hardware

[AssadHashmi]

When adding SVE signal context support (#6725), linux.thread-reset started failing intermittently on non-SVE hardware.

To replicate the failure, build in DEBUG or RELEASE mode and run the unit test. It will fail almost all of the time in RELEASE mode and will fail most of the time in DEBUG mode. Attempts to debug using GDB or just with -debug -loglevel will result in the test passing almost all of the time.

[derekbruening]

When adding SVE signal context support (#6725), linux.thread-reset started failing intermittently on non-SVE hardware.

That sounds like there could be a regression introduced by the SVE changes? Is it possible to bisect the changes and isolate which change causes the failures?