feat: throw and nativeThrow in return reachability analysis

[anton-trunov]

Closes #421

• I have updated CHANGELOG.md
• I have added tests to demonstrate the contribution is correctly implemented: this usually includes both positive and negative tests, showing the happy path(s) and featuring intentionally broken cases
• I have run all the tests locally and no test failure was reported
• I have run the linter, formatter and spellchecker
• I did not do unrelated and/or undiscussed refactorings

[novusnota]

Cool! There are also nativeThrowWhen() and nativeThrowUnless(), but those aren't checked as easily :)

Missed cases

[anton-trunov]

There are also nativeThrowWhen() and nativeThrowUnless(), but those aren't checked as easily :)

The return reachability analysis we use is really dumb: it won't check if an arbitrary function always throws and it won't try to determine if the condition is always true/false for nativeThrowWhen() and nativeThrowUnless(), it won't analyze assembly wrapped into a FunC function, etc.