sxsyn, allow $1 as identifier

src/u_sxsyn.pas

@@ -675,21 +675,12 @@ begin
   while fTokStop <= fLineBuf.length do
   begin
     case fLineBuf[fTokStop] of
-      '_', 'a'..'z', 'A'..'Z':
+      '_', 'a'..'z', 'A'..'Z', '0'..'9':
       begin
         oneChr    := true;
         fTokStop  += 1;
         continue;
       end;
-      '0' .. '9':
-      begin
-        if oneChr then
-        begin
-          fTokStop  += 1;
-          continue;
-        end
-        else break; // e.g $0
-      end
       else break;
     end;
   end;