Apparently I2556b39d did not really add v3.4.0 of es5-shim but rather a newer version affected by https://github.com/es-shims/es5-shim/issues/253. This makes es5-shim unusable for its primary purpose in MediaWiki: providing compatibility with old versions of IE.
I ran into this bug, which causes errors even for (non-core) site JS, while working on a user script on English Wikipedia.
Version: 1.24rc
Severity: normal
See Also:
https://github.com/es-shims/es5-shim/issues/253
Change 144359 had a related patch set uploaded by PleaseStand:
Update es5-shim to bb74ba2 (2014-06-25)
(In reply to Kevin Israel (PleaseStand) from comment #0)
I ran into this bug, which causes errors even for (non-core) site JS, while
working on a user script on English Wikipedia.
I think this is because of MultimediaViewer (see also bug 67590).
My motivation for using es5-shim and reporting this bug, however, is that I have a user script on English Wikipedia that otherwise would need its own date parsing code https://en.wikipedia.org/w/index.php?title=User:PleaseStand/userinfo.js&diff=615803540&oldid=603055971.
Change 145400 had a related patch set uploaded by Jforrester:
Update es5-shim to latest master (40181d720e07)
Change 145401 had a related patch set uploaded by Jforrester:
Update es5-shim to latest master (40181d720e07)
[Backport was merged into 1.24wmf12 and 1.24wmf13 upon a time, hence setting Backport_WMF flag to +]