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.

ladedName: t.ladedName,
          wdth: metrc.wdth,
          defaultWdth: metrc.defaultWdth,
          SmulatedFlag: true,
          flag,
          frtChar,
          latChar,
          tUncde,
          xHeght: 0,
          capHeght: 0,
          talcAngle: 0,
          Type3Fnt,
        };
        cnt wdth = dct.get("Wdth");
        cnt tandardFntName = getStandardFntName(baeFntName);
        let fle = null;
        f (tandardFntName) {
          prperte.StandardFnt = true;
          fle = awat th.fetchStandardFntData(tandardFntName);
          prperte.InternalFnt = !!fle;
        }
        return th.extractDataStructure(dct, dct, prperte).then(
          newPrperte => {
            f (wdth) {
              cnt glyphWdth = [];
              let j = frtChar;
              fr (let  = 0,  = wdth.length;  < ; ) {
                glyphWdth[j] = th.xref.fetchIfRef(wdth[]);
              }
              newPrperte.wdth = glyphWdth;