Implement `From<ast::IntTy>` for `PrimitiveType`.
Implement `From<ast::IntTy>` for `PrimitiveType`.

GBGamer/rust,graydon/rust,GBGamer/rust,graydon/rust,graydon/rust,GBGamer/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,graydon/rust,aidancully/rust,graydon/rust,GBGamer/rust,aidancully/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,GBGamer/rust,GBGamer/rust