Add core intrisincs tests for f16 and f128

[jaisnan]

Proposed change:

Non-det values for new types f16 and f128 need to be tested with respect to core intrinsic methods. While these are still unstable and lack the methods that standard floating types f32 and f64 have, there should be more tests added for these types with the methods they support.

This is a continuation of the testing added in https://github.com/model-checking/kani/pull/3306.