set flag ShuntingYardParser_debug.

svoid test_ShuntingYardParser() {
  testFunctionValues(s -> ShuntingYardParser(s/S)!,
    "1+2*3", ll("1", "2", "3", "*", "+"),
    "-3e2", ll("300.0", "u-"),
    "-(1+2)", ll("1", "2", "+", "u-"),
  );
}