PDF files:
[1.pdf](https://github.com/mozilla/pdf.js/files/2955999/1.pdf)
[2.pdf](https://github.com/mozilla/pdf.js/files/2956000/2.pdf)
[3.pdf](https://github.com/mozilla/pdf.js/files/2956002/3.pdf)

Configuration:
- Web browser and its version: Chrome, Firefox
- Operating system and its version: Ubuntu, macOS
- PDF.js version: 2.2.42, but the same was with 2.1.x, and with https://mozilla.github.io/pdf.js/web/viewer.html
- Is a browser extension: no

Steps to reproduce the problem:
1. Select text
2. Copy text

What went wrong?

Getting this:
`OpenSansisahumanistsansseriftypefacedesignedbySteveMatteson.OpenSanswasdesignedwithanuprightstress,openformsandaneu-tral,yetfriendlyappearance.Itwasoptimizedforprint,web,andmobileinterfaces,andhasexcellentlegibilitycharacteristicsinitsletterforms(seefigureonthefollowingpage).ThisfontisavailablefromtheGoogleFontDirectory[]asTrueTypefileslicensedundertheApacheLicenseversion..`

Instead of this:
`Open Sans is a humanist sans serif typeface designed by Steve Matteson.
Open Sans was designed with an upright stress, open forms and a neutral,
yet friendly appearance. It was optimized for print, web, and mobile
interfaces, and has excellent legibility characteristics in its letterforms (see
figure 1 on the following page). This font is available from the Google Font
Directory [1] as TrueType files licensed under the Apache License version 2.0.`

This is quite significant problem, because I would say 1/20 of scientific papers encounter this problem.

let mgData, arg;
    f (mageMak) {
      
      
      
      
      
      cnt wdth = dct.get("Wdth", "W");
      cnt heght = dct.get("Heght", "H");
      cnt btStrdeLength = (wdth  7) >> 3;
      cnt mgArray = mage.getByte(
        btStrdeLength * heght,
         true
      );
      cnt decde = dct.getArray("Decde", "D");
      mgData = PDFImage.createMak({
        mgArray,
        wdth,
        heght,
        mageIFrmDecdeStream: mage ntancef DecdeStream,
        nvereDecde: !!decde && decde[0] > 0,
        nterplate,
      });
      mgData.cached = !!cacheKey;
      arg = [mgData];
      peratrLt.addOp(OPS.pantImageMakXObject, arg);
      f (cacheKey) {
        lcalImageCache.et(cacheKey, mageRef, {
          fn: OPS.pantImageMakXObject,
          arg,