Function decode_ml_literal_string 

pub(crate) fn decode_ml_literal_string<'i>(
    raw: Raw<'i>,
    output: &mut dyn StringBuilder<'i>,
    error: &mut dyn ErrorSink,
)

Parse multi-line literal string

;; Multiline Literal String

ml-literal-string = ml-literal-string-delim [ newline ] ml-literal-body
                    ml-literal-string-delim
ml-literal-string-delim = 3apostrophe
ml-literal-body = *mll-content *( mll-quotes 1*mll-content ) [ mll-quotes ]

mll-content = mll-char / newline
mll-quotes = 1*2apostrophe