Merge pull request #4274 from kumpera/cctor-abort

[runtime] Latest attempt at the cctor abort race. All tests passing locally.

diff --cc mono/metadata/icall.c
Simple merge

diff --cc mono/metadata/object-internals.h
Simple merge

diff --cc mono/metadata/object.c
Simple merge

diff --cc mono/metadata/threads-types.h
Simple merge

diff --cc mono/metadata/threads.c
Simple merge