Sourcery crashes on \r\n (a.k.a. DOS- or Windows-style) line-endings

[fischman-bcny]

Sourcery crashes on \r\n (a.k.a. DOS- or Windows-style) line-endings

[art-divin]

I did an analysis, and the following was discovered:

1. SourceryFramework/Parsing/Sources/Utils/StringView.swift parses input and uses CharacterSet for recognizing newline tokens \u{000A}\u{000D} (see StringView.swift:214 and StringView.swift:173)
2. Reference for the CharacterSet mentions link which has newline semantics described as line-break → U+000D followed by U+000A.
3. Since CharacterSet is used, the sequence of the characters is undetermined when used in string.components(separatedBy: CharacterSet("\u{000A}\u{000D}"))

Comparing to how TokenTrivia is parsing input, it mentions case carriageReturnLineFeeds(Int) as "newline consists of contiguous '\r' and '\n' characters". Thus, when parsed, expression struct S {}\r\nprotocol AP {}\r\n is represented as 3 lines in total, compared to how StringView.swift in Sourcery ends up with 5 lines in total.

Notes:

\u{000D}\u{000A} is essentially \r\n in unicode