If they're in the header and the header is used in multiple .cpp, there
are multiple definitions. Oddly it did not lead to an error, but there
were multiple structs of the same topic but with different adresses.
This lead to a metadata mismatch, when running eg:
uorb_tests
uorb_tests latency_test
It makes more sense to set the optimization flags on a platform basis
instead of individually for each module. This allows for different
optimization options for SITL, NuttX, Snapdragon, etc.
This is required for the logger, we just manually add the padding bytes
what would otherwise be done by the compiler. Additionally we reorder
the fields by type, so that padding is only necessary for nested types.
Beat Küng