Keywords that are both storage class and statements are not highlighted appropriately

[Jesse Phillips]

Several keywords (e.g., in, out, inout) are both storage class and statements, depending on their context. Perhaps use pattern matching to figure out which and highlight appropriately. For now I have made such keywords storage classes so their highlighting is consistent with other keywords that are commonly used with them, but are true storage classes, such as lazy. Similarly, I made some statement keywords (e.g. body) storage classes.

-- Jason Mills