SplitCallArguments now skips C# line (`//`) and block (`/* */`) comments when
tokenizing the argument list, so a comma inside a comment no longer produces a
spurious arg-count mismatch. IsNumericLiteral now explicitly rejects tokens
whose first non-sign character is `_` or a letter (e.g. `_2`), and restricts
underscore digit-separators to positions after at least one digit, preventing
identifier-shaped tokens from being inferred as Integer/Float.
Joseph Doherty
a8e9e9952d