Attach (recommended) or Link to PDF file here:  [test.pdf](https://akmer.aikucun.com/a94a8fe5ccb19ba61c4c0873d391e987982fbbd3_1616477914120_83.pdf)


Configuration:
- Web browser and its version: chrome 87.0.4280.88
- Operating system and its version: windows10
- PDF.js version: 2.6.347
- Is a browser extension:

Steps to reproduce the problem:
1. just open 

What is the expected behavior? (add screenshot)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/17724610/112087066-473f8f80-8bc8-11eb-8efb-56139ec42a9c.png)

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

this.str = str;
    this.dict = str.dict;
    this.firstDigit = -1;
    
    
    if (maybeLength) {
      maybeLength = 0.5 * maybeLength;
    }
    DecodeStream.call(this, maybeLength);
  }
  AsciiHexStream.prototype = Object.create(DecodeStream.prototype);
  AsciiHexStream.prototype.readBlock = function AsciiHexStream_readBlock() {
    var UPSTREAM_BLOCK_SIZE = 8000;
    var bytes = this.str.getBytes(UPSTREAM_BLOCK_SIZE);
    if (!bytes.length) {
      this.eof = true;
      return;
    }
    var maxDecodeLength = (bytes.length + 1) >> 1;
    var buffer = this.ensureBuffer(this.bufferLength + maxDecodeLength);
    var bufferLength = this.bufferLength;
    var firstDigit = this.firstDigit;
    for (var i = 0, ii = bytes.length; i < ii; i++) {
      var ch = bytes[i],
        digit;
      if (ch >=  0x30 && ch <=  0x39) {
        digit = ch & 0x0f;
      } else if (
        (ch >=  0x41 && ch <=  0x46) ||