Reads a single line comment
function() {
    while (this.offset < this.size) {
      const ch = this.input();
      if (ch === "\n" || ch === "\r") {
        return this.tok.T_COMMENT;
      } else if (
        ch === "?" &&
        !this.aspTagMode &&
        this._input[this.offset] === ">"
      ) {
        this.unput(1);
        return this.tok.T_COMMENT;
      } else if (
        ch === "%" &&
        this.aspTagMode &&
        this._input[this.offset] === ">"
      ) {
        this.unput(1);
        return this.tok.T_COMMENT;
      }
    }
    return this.tok.T_COMMENT;
  }