Address NRT issues found by targeting net5.0#50895

Merged

jasonmalinowski merged 13 commits intodotnet:mainfrom huoyaoyuan:net5.0-nrt

Mar 5, 2021

+50-83

Commits on Jan 29, 2021

Commits on Jan 30, 2021

Commits on Feb 26, 2021

Remove reflection of IsThreadPoolThread.
huoyaoyuan
committed

Commits on Feb 27, 2021