if f is a contextually typed function expression (section 4.9.3), the inferred return type is the union type (section 3.3.4) of the types of the return statement expressions in the function body, ignoring return statements with no expressions.
Otherwise, the inferred return type is the first of the types of the return statement expressions in the function body that is a supertype (section 3.8.3) of each of the others, ignoring return statements with no expressions. A compile-time error occurs if no return statement expression has a type that is a supertype of each of the others.
In effect this fixes#62.
Also
- Changes the error message for get accessors lacking return expressions.
- Actually checks for return expressions instead of return statements for get-accessors.
- Removes fancy quotes.
- Corrects errors in the compiler caught by the new check.
- Simplified `checkAndAggregateReturnTypes` by extracting it out to `visitReturnStatements`.
