Viewer:  https://mozilla.github.io/pdf.js/web/viewer.html
Chrome on Windows 10
When the attached PDF file is viewed, some of the fonts display as garbled text. 
[Arial, Courier, Times New Roman]
The file views correctly in Adobe Reader.
[fff.pdf](https://github.com/mozilla/pdf.js/files/4652174/fff.pdf)

const locaEntries = [];
      
      for (i = 0, j = 0; i < numGlyphs + 1; i++, j += itemSize) {
        let offset = itemDecode(locaData, j);
        if (offset > oldGlyfDataLength) {
          offset = oldGlyfDataLength;
        }
        locaEntries.push({
          index: i,
          offset,
          endOffset: 0,
        });
      }
      locaEntries.sort((a, b) => {
        return a.offset - b.offset;
      });
      
      
      
      for (i = 0; i < numGlyphs; i++) {
        locaEntries[i].endOffset = locaEntries[i + 1].offset;
      }
      
      locaEntries.sort((a, b) => {
        return a.index - b.index;
      });
      const missingGlyphs = Object.create(null);
      let writeOffset = 0;
      itemEncode(locaData, 0, writeOffset);
      for (i = 0, j = itemSize; i < numGlyphs; i++, j += itemSize) {