Add more Ruby type conversions

[zah]

Summary

• support additional Ruby types in pure recorder and native tracer
• add a new test program using floats, hashes, ranges, sets, times, regexps and structs
• update fixtures accordingly

Testing

• just build-extension
• just test (fails: undefined method find_unresolved_default_spec when requiring stdlib)

[zah]

Work will continue in another PR