Native unit test runner intermittently reports SIGSEGV (segmentation fault)

[adbancroft]

Background: Speedino generates test coverage using the native platform

Problem: the test runner will intermittently report Program received signal SIGSEGV (Segmentation fault), which skews the coverage numbers for that commit.

Examples: These are all for the same commit, with no code changes:

1. Run #1 - fails after the last test in the 'test_pages` suite.
2. Run #2 - fails after the last test in the 'test_sensors` suite.
3. Run #3 - succeeds.

Notes:

• The native test program always returns 0 (to the shell)
• When the error occurs, it's always after the last test in the test suite has passed (as shown in the linked examples).