Merge branch 'hai/stdpp_update' into 'master'

update stdpp

See merge request FP/iris-coq!68
3 jobs for master in 3 minutes and 49 seconds (queued for 1 second)
Status Name Job ID Coverage
  Build
passed build-coq8.6.1 #3703
fp-timing

00:03:34

passed build-coq8.7 #3702
fp-timing

00:03:27

 
  Opam
passed opam #3704

00:00:13