LibRegex: Use a match table for character classes

Generate a sorted, compressed series of ranges in a match table for
character classes, and use a binary search to find the matches.
This is about a 3-4x speedup for character class match performance. :^)

Userland/Libraries/LibRegex/Forward.h

@@ -9,6 +9,8 @@
 #include <AK/Types.h>
 
 namespace regex {
+struct CompareTypeAndValuePair;
+
 enum class Error : u8;
 class Lexer;
 class PosixExtendedParser;