Added AS3 P-code keyword "Unknown(N)", where N is index. For constants out of bounds. (mostly in dead code)

Fixed AS3 Deobfuscation causing invalid jump offsets for files with constant indices out of bounds

libsrc/ffdec_lib/lexers/actionscript3_pcode_hilight.flex

@@ -163,6 +163,7 @@ ExceptionTarget = "exceptiontarget "{PositiveNumberLiteral}":"
   "MultinameL"                 |
   "MultinameLA"                |
   "TypeName"                   |
+  "Unknown"                    |
   "null"                       {  return token(TokenType.KEYWORD2);}
   "("                          {  return token(TokenType.OPERATOR,PARAN); }
   ")"                          {  return token(TokenType.OPERATOR,-PARAN); }