Allow block comments for the table in the code.

Switching to trailing comments doesn't read as well, and swift-format doesn't
actually align all the line trailing comments, so the one line that is shorted
would get it's comment indented compared to the rest so it doesn't read as well.

Author: thomasvl

Sources/SwiftProtobuf/JSONScanner.swift

@@ -85,6 +85,7 @@ private func fromHexDigit(_ c: UnicodeScalar) -> UInt32? {
 // known as "base64url" or the "URL-safe alphabet".
 // Note that both "-" and "+" decode to 62 and "/" and "_" both
 // decode as 63.
+// swift-format-ignore: NoBlockComments
 let base64Values: [Int] = [
     /* 0x00 */ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
     /* 0x10 */ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,