This update covers 797 commits, including 121 new upstream commits I've never filed a bug on before. (They're the top 121.). 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=271888e8af1ccfcd4e8510d8568d304f8c41c610

All jobs completed, we found the following issues.

Known Issues (From Taskcluster):

• hazard-linux64-shell-haz/debug (CuyLowwSSYaxg9X5ALhIhQ) - new failure not classified
• spidermonkey-sm-arm64-sim-linux64/debug (bJPA5L3pRF23PgIWG9dggw) - new failure not classified
• spidermonkey-sm-linux64-wasi/opt (AcoK4RCsQ7Gs9dUtW7H3jQ) - new failure not classified
• spidermonkey-sm-gdb-linux64/debug (BkX78MHxQmm3rWcGgrYygA) - new failure not classified
• spidermonkey-sm-nojit-linux64/opt (ElSs9FhOTx-AQp_Y-TxviQ) - new failure not classified
• spidermonkey-sm-asan-linux64/opt (C1hqWcGZQJC2Ubb-n2WbfA) - new failure not classified
• spidermonkey-sm-temporal-linux64/debug (A5JXWG8zR8OrjvpceA4bWA) - new failure not classified
• spidermonkey-sm-plain-linux64/debug (bhLvfZLjTLyFdc2Epyc-GA) - new failure not classified
• spidermonkey-sm-arm-sim-linux32/debug (Ta-r1HJxTY2F8MJglWjffQ) - new failure not classified
• spidermonkey-sm-compacting-linux64/debug (D6KhDAJkRbOW6IR8t0kdWA) - new failure not classified
• spidermonkey-sm-rootanalysis-linux64/debug (YaqOaLivSgeRUebq_hW0RQ) - new failure not classified
• spidermonkey-sm-tsan-linux64/opt (DQIy7jcPQseYF9zXy14XSw) - new failure not classified
• spidermonkey-sm-fuzzing-linux64/opt (FeLU6PRASBmoorOvmYfPEg) - new failure not classified
• spidermonkey-sm-wasm-no-experimental-linux64/debug (JLAb2PkBQQu1hOjPueAsVg) - new failure not classified
• spidermonkey-sm-plain-linux64/opt (Ug2XT_j_S32EKzBynQjEug) - new failure not classified
• spidermonkey-sm-package-linux64/opt (RSqdAd9yQMeBUlvqgDoVcg) - new failure not classified
• spidermonkey-sm-rt-linux64/debug (GKiBmG3PR5iK6i-1hRkZ-g) - new failure not classified
• spidermonkey-sm-nonunified-linux64/debug (MpVrFtnIQo6fefepW1kUoA) - new failure not classified
• spidermonkey-sm-fuzzilli-linux64/debug (HCVb4gsRRQ26sR5s3CjrjQ) - new failure not classified
• spidermonkey-sm-linux64-wasi-intl/opt (RdsXos_xRcSkTLgyC5zGbQ) - new failure not classified
• spidermonkey-sm-plain-linux32/debug (QhJGLJ1kTWy2vWcGZv2dUA) - 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).