Attach (recommended) or Link to PDF file here:
[example.pdf](https://github.com/mozilla/pdf.js/files/6916129/example.pdf)

Configuration:
- Web browser and its version: Chrome, Firefox
- Operating system and its version: all
- PDF.js version: various versions, including 2.11.54
- Is a browser extension: no

Screenshot with visible textLayer:
![Screenshot from 2021-08-02 13-05-03](https://user-images.githubusercontent.com/6362989/127844878-f85e291f-2060-4028-be09-7835f32ccfaa.png)

Which means some letters at the beginning/end of text selection are missing when copying text.

const angle = Math.floor(properties.italicAngle * 2 ** 16);
  return (
    "\x00\x03\x00\x00" + 
    string32(angle) + 
    "\x00\x00" + 
    "\x00\x00" + 
    string32(properties.fixedPitch ? 1 : 0) + 
    "\x00\x00\x00\x00" + 
    "\x00\x00\x00\x00" + 
    "\x00\x00\x00\x00" + 
    "\x00\x00\x00\x00"
  ); 
}
function createPostscriptName(name) {
  
  return name.replace(/[^\x21-\x7E]|[[\](){}<>/%]/g, "").slice(0, 63);
}
function createNameTable(name, proto) {
  if (!proto) {