Provide sanity test cases for NANO_ESF/NANO_ISF structures

[zephyrbot]

Reported by Andrew Boie:

These data structures depend heavily on the number and ordering that registers are pushed onto the stack during an exception and are susceptible to bit-rot. Devise a testcase for each target arch that verifies that the NANO_ESF and NANO_ISF structs created during exception/irq handling are laid out correctly.

Can probably do this by pre-populating the desired registers with sentinel values and then triggering the exception and verifying the state.

(Imported from Jira ZEP-985)

[zephyrbot]

by Sharron LIU:

whitebox test point covered by development test.

[zephyrbot]

by Mark Linkmeyer:

Fixing incorrect priority

[zephyrbot]

by Andrew Boie:

Robert Beatty Mark Linkmeyer
Will not be done for 1.7. Recommend we set to "Future" given other priorities.

[zephyrbot]

by Robert Beatty:

Andrew Boie , moving to {{v1.9}} as there is not immediate commit for {{v1.8}}

[nashif]

@andrewboie is this still need, should we assign to someone else to create tests?

[andrewboie]

@nashif yes this should be tested.

[nashif]

@kumarvikash1 please assign someone to create tests for this.

[galak]

@kumarvikash1 any updates on getting someone assigned for this?

[galak]

Is this still relevant?