Rules for source dump character escape changed in V8

[Slava Egorov]

As a result unescaping code

irhydra/lib/src/modes/v8/code_parser.dart

Lines 119 to 129 in 13a2cd5

 try { 
 if (lines.length == 1) { 
   final String line = lines.first; 
   if (line.contains(r"\x0a")) { 
     lines = line.replaceAllMapped(new RegExp(r"\\(x[a-f0-9][a-f0-9]|u[a-f0-9][a-f0-9][a-f0-9][a-f0-9])"), (m) => new String.fromCharCode(int.parse(m.group(1).substring(1), radix: 16))) 
         .split('\n'); 
   } 
 } 
 } catch (e) { 
   print(e); 
 } 

no longer works. It is not obvious to me how to fix this because I don't see a backwards compatible way to detect whether escaping was applied or not.