This update covers 848 commits, including 51 new upstream commits I've never filed a bug on before. (They're the top 51.). Here are the overall diff statistics.

js/src/irregexp/imported/gen-regexp-special-case.cc | 48 ---------------------
js/src/irregexp/imported/regexp-ast.h | 6 --
js/src/irregexp/imported/regexp-compiler-tonode.cc | 25 +----------
js/src/irregexp/imported/regexp-interpreter.cc | 20 ++++----
js/src/irregexp/imported/regexp-macro-assembler.cc | 26 +++++-----
js/src/irregexp/imported/regexp-parser.cc | 2 +-
js/src/irregexp/imported/special-case.h | 10 ----
js/src/irregexp/moz.yaml | 4 +-
8 files changed, 27 insertions(+), 114 deletions(-)

I've submitted a try run for this commit: https://treeherder.mozilla.org/jobs?repo=try&revision=fee755c4b9c04003e76132adb59a3f21b72960d0

All jobs completed, we found the following issues.

Known Issues (From Taskcluster):

• spidermonkey-sm-arm-sim-linux32/debug (XUbx9dAdRsGN0vUVHjJfjw) - new failure not classified
• spidermonkey-sm-linux64-wasi-intl/opt (dKkdO7FoSL-7T-JPvAwwcQ) - new failure not classified
• spidermonkey-sm-arm64-sim-linux64/debug (bMkGU7liRdadwaD-jAZprQ) - new failure not classified
• spidermonkey-sm-rootanalysis-linux64/debug (MuRPBlZdRNWqhFufO0qSvQ) - new failure not classified
• spidermonkey-sm-plain-linux64/debug (BuRahzRkTSWR74I-ONhzNg) - new failure not classified
• spidermonkey-sm-temporal-linux64/debug (DdkRnYkTS9a5REdG6BHjIQ) - new failure not classified
• spidermonkey-sm-wasm-no-experimental-linux64/debug (F9AKcZ0RRMapYy7qnTrNUw) - new failure not classified
• spidermonkey-sm-compacting-linux64/debug (KPcIaWWeRZG_2ft8Rg1ZNQ) - new failure not classified
• spidermonkey-sm-fuzzilli-linux64/debug (VIw8s_5rT2qCV1dCHOHpTg) - new failure not classified
• spidermonkey-sm-package-linux64/opt (aZ6TojbYQU6YD1AepE5zag) - new failure not classified
• spidermonkey-sm-plain-linux64/opt (O5rE4acGQJ2AOpkX0Z3Y_w) - new failure not classified
• spidermonkey-sm-nonunified-linux64/debug (OafVPTF0Rm69MOQw2dI6nA) - new failure not classified
• spidermonkey-sm-fuzzing-linux64/opt (D3oVG8bdSECTGwU9oWKesA) - new failure not classified
• spidermonkey-sm-gdb-linux64/debug (KSFqD7mKQyKy84QNhVVYvA) - new failure not classified
• spidermonkey-sm-asan-linux64/opt (JadtI67ATRaosSfLF-jJEQ) - new failure not classified
• spidermonkey-sm-tsan-linux64/opt (Ijs_8P49RdKjjMaPkBfBNw) - new failure not classified
• spidermonkey-sm-plain-linux32/debug (IfX3hgn8TIGPGbXRfvxwUg) - new failure not classified
• hazard-linux64-shell-haz/debug (KcYNkapqR36uVD_6OWqkCQ) - new failure not classified
• spidermonkey-sm-rt-linux64/debug (LEjxOLiESSCRWsoLUZCang) - new failure not classified
• spidermonkey-sm-nojit-linux64/opt (cVhQzrxMRruaFv2-TTLW4Q) - new failure not classified
• spidermonkey-sm-linux64-wasi/opt (BIoTx95JTe-9BvXJWmLqCg) - new failure not classified

These failures may mean that the library update succeeded; you'll need to review
them yourself and decide. If there are lint failures, you will need to fix them in
a follow-up patch. (Or ignore the patch I made, and recreate it yourself with
./mach vendor js/src/irregexp/moz.yaml.)

In either event, I have done all I can, so you will need to take it from here.
When reviewing, please note that this is external code, which needs a full and
careful inspection - not a rubberstamp.

This bug is being closed because a newer revision of the library is available.
This bug will be marked as a duplicate of it (because although this bug is older, it is superseded by the newer one).