According to "The table directory" under https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6.html#Directory, TrueType font tables should have `uint32` checksums.
This is something that I noticed, and was initially confused about, while debugging a TrueType issue.
As far as I can tell, the current (`int32`) checksums we use doesn't cause any issues in practice. However, I do think that this should be addressed to agree with the specification, and to reduce possible confusion when reading the font code.
This is regression from PR 7063, causing `gulp importl10n` to fail:
```
$ gulp importl10n
[19:45:02] Using gulpfile c:\Users\Jonas\Git\pdfjs\gulpfile.js
[19:45:02] Starting 'importl10n'...
Downloading ach...
[19:45:02] 'importl10n' errored after 4.42 ms
[19:45:02] Error: EEXIST, file already exists 'c:\Users\Jonas\Git\pdfjs\l10n\ach
'
at Error (native)
at Object.fs.mkdirSync (fs.js:747:18)
at downloadLanguageFiles (c:\Users\Jonas\Git\pdfjs\external\importL10n\local
es.js:59:8)
at next (c:\Users\Jonas\Git\pdfjs\external\importL10n\locales.js:90:5)
at Object.downloadL10n (c:\Users\Jonas\Git\pdfjs\external\importL10n\locales
.js:91:5)
at Gulp.<anonymous> (c:\Users\Jonas\Git\pdfjs\gulpfile.js:92:11)
at module.exports (c:\Users\Jonas\Git\pdfjs\node_modules\gulp\node_modules\o
rchestrator\lib\runTask.js:34:7)
at Gulp.Orchestrator._runTask (c:\Users\Jonas\Git\pdfjs\node_modules\gulp\no
de_modules\orchestrator\index.js:273:3)
at Gulp.Orchestrator._runStep (c:\Users\Jonas\Git\pdfjs\node_modules\gulp\no
de_modules\orchestrator\index.js:214:10)
at Gulp.Orchestrator.start (c:\Users\Jonas\Git\pdfjs\node_modules\gulp\node_
modules\orchestrator\index.js:134:8)
```
Pass the `PDFJS.postMessageTransfer` parameter to the worker, so that the `MessageHandler` can be setup correctly in `createDocumentHandler` (issue 6957)
Currently there's a lot of duplicate code for non-embedded `toFontChar`, which this patch simplifies by extracting the code into a helper function instead.
This patch adds a `getUnicodeForGlyph` helper function, which is used to recover Unicode values for non-standard glyph names.
Some PDF generators, e.g. Scribus PDF, use improper `uniXXXX` glyph names which breaks the glyph mapping. We can avoid this by converting them to "standard" glyph names instead.
Fixes https://bugzilla.mozilla.org/show_bug.cgi?id=1132849.
Fixes 6893.
Fixes 6894.
[PDFThumbnailView] Re-factor the `canvas` to `image` conversion such that we always render to a `canvas`, and then replace it with an `image` once rendering is done
