A lot of these were pointless; the function being called took a StringData and there was no need to be constructing a std::string. Some actually do need to take a std::string because they need the string to be null-terminated (and we don't have a non-owning type which guarantees that), so we might as well use the one we already have rather than returning it as a StringData.

Declaring these simple getters in the header makes it so that they can be inlined out of existence without relying on LTO.