add method to construct def site path as a vec of idents
add method to construct def site path as a vec of idents

like std_path but used dummy span for all path elements and does not perpend kw:DollarCrate

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