AthenaAuditors: Make FPEAuditor behave gracefully on arm.
On aarch64, have FPEAuditor print a warning when stack trace collection is requested, rather than crashing.
Fixes unit test failure in MuonGeoModelTestR4.
On aarch64, have FPEAuditor print a warning when stack trace collection is requested, rather than crashing.
Fixes unit test failure in MuonGeoModelTestR4.