fails:Regexp.compile given a String with escaped characters returns a Regexp with source String having US-ASCII encoding if only 7-bit ASCII characters are present regardless of the input String's encoding
fails:Regexp.compile given a String with escaped characters returns a Regexp with source String having US-ASCII encoding if UTF-8 escape sequences using only 7-bit ASCII are present
fails:Regexp.compile given a String uses ASCII_8BIT encoding if third argument is 'n' or 'none' (case insensitive) and non-ascii characters
