Bump std++ (pattern matching bind).

4 jobs for master in 16 minutes and 31 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #79815
fp
build-coq.8.10.2

00:11:20

canceled #79814
fp-timing
build-coq.8.11.2

canceled #79813
fp
build-coq.8.12.dev

00:16:31

passed #79816
fp
build-coq.8.9.1

00:10:44