Mac Arm64 Architecture fpe handling

[johnson452]

Summary

Handles floating pointing exception when compiled on arch64 and Apple (for M1 and M2 chips). Only works for overflow currently, there is an apparent limitation to these architectures for catching division by zero.

Additional background

SIGILL instead of SIGFPE is needed to catch arch64 signals, see ref: https://developer.apple.com/forums/thread/689159

Checklist

The proposed changes:

• fix a bug or incorrect behavior in AMReX
• add new capabilities to AMReX
• changes answers in the test suite to more than roundoff level
• are likely to significantly affect the results of downstream AMReX users
• include documentation in the code and/or rst files, if appropriate

[WeiqunZhang]

We need to restore the previous signal handler for SIGILL in amrex::Finalize(). We could also update BLBackTrace::handler to print out a message about the type of signal.

[atmyers]

This worked for me on my M1 mac.