Enhancements

• Support static variables in extensions (#74).
• Raise warnings when unsupported initializers are found in structs (#70).
• Support let _ = <expression> (#69).

Bugfixes

• Support single-expression functions (#75) and getters (#80), both by @sgade.
• Avoid translating description as toString() when we know the type doesn't conform to CustomStringConvertible (#71).
• Fix labeled returns on closures when they refer to functions with named arguments (#67).

For the future

• Lots of work on supporting SourceKit and SwiftSyntax, which would solve a lot of bugs and let us support Swift 5.3.