SynEdit: fix endless XML HL, do not return empty tokens.

components/synedit/synhighlighterxml.pas

@@ -792,6 +792,7 @@ end;
 procedure TSynXMLSyn.Next;
 begin
   fTokenPos := Run;
+  while fTokenPos = Run do begin
     case fRange of
     rsText:
       begin
@@ -816,6 +817,9 @@ begin
     else
       fProcTable[fLine[Run]]();
     end;
+    if fTokenId = tkNull then // EOL
+      break;
+  end;
 end;
 
 function TSynXMLSyn.NextTokenIs(T : String) : Boolean;