refactor Method definition to make space for macros
test case for method macros
macro method test case fix
update fold_method to return a smallvector

This is nice for macros, to allow them to expand into multiple methods
remove no-stmt check

nothing wrong with a statement expanding into 0 stmts, that I can see.
macro in method position parsing
add make_method method to MacResult trait

this allows macro results to be parsed as methods
expansion abstraction
macro expansion for methods