Log Message:
gperftools 2.6.1 is out! This is mostly bug-fixes release.

* issue 901: build issue on OSX introduced in last-time commit in 2.6
  was fixed (contributed by Francis Ricci)

* tcmalloc_minimal now works on 32-bit ABI of mips64. This is issue
  845. Much thanks to Adhemerval Zanella and github user mtone.

* Romain Geissler contributed build fix for -std=c++17. This is pull
  request 897.

* As part of fixing issue 904, tcmalloc atfork handler is now
  installed early. This should fix slight chance of hitting deadlocks
  at fork in some cases.