When delim is "Auto", Utils.charRep("Auto") returns undefined,
causing data.split(undefined) to return the entire string as a
single element. This meant only the first number was parsed.
Fix by splitting on a regex /[^\d-]+/ for Auto mode, consistent
with how fromHex handles its Auto delimiter. Existing delimiter
behavior is unchanged.
Adds test cases for Auto delimiter with space, comma, and mixed
separators.
Fixes#2217
Ref: #2221 (closed due to unsigned CLA)
ae0e989635