- refactor makeConcat/makeConcatWithArguments methods to remove the generateRecipe argument
- fold back-to-back constants into one when parsing recipe, which allows the prepender logic to be simplified
- do input checking in the parse pass
- get rid of the Recipe and RecipeElement classes by representing the parsed recipe as a list of Strings which are either null (argument slot) or not (constant)
- eagerly rebind on setup of those method handles that we'll always transform (transforming will call rebind() anyway which will now be a no-op)
- simplify filtering logic by picking up the erased type, so that we can do c == Object.class rather than !c.isPrimitive