Backport (unmerged) changes for further cgroupv2 compat#25

Merged

maleadt merged 2 commits intojulia-uv2-1.44.2from

tb/available_memory

Sep 19, 2022

Commits on Sep 19, 2022

Fix the returned value of constrained memory getters.
maleadt
committed
Add uv_get_available_memory to query free memory respecting constraints.
maleadt
committed