Simplify initialization of CILJit singleton

[jkotas]

No description provided.

[ghost]

Tagging subscribers to this area: @JulieLeeMSFT, @jakobbotsch
See info in area-owners.md if you want to be subscribed.

Issue Details

---

null

Author:	jkotas
Assignees:	-
Labels:	area-CodeGen-coreclr
Milestone:	-

[jakobbotsch]

LGTM provided CI is green

[jkotas]

System.Net.WebSockets.Client.Tests crashed on Libraries Test Run checked coreclr Linux_musl x64 Debug. Stacktrace:

Call Site
libcoreclr!Object::GetGCSafeMethodTable [/__w/1/s/src/coreclr/vm/object.h @ 446] libcoreclr!Object::ValidateInner+0x1b0
libcoreclr!Object::Validate+0x8a [/__w/1/s/src/coreclr/vm/object.cpp @ 1124] libcoreclr!OBJECTREF::OBJECTREF+0xfa [/__w/1/s/src/coreclr/vm/object.cpp @ 1124] libcoreclr!ObjectFromHandle+0x2c [/__w/1/s/src/coreclr/vm/gchandleutilities.h @ 44] libcoreclr!MarshalNative::GCHandleInternalGet+0x50

Tracked by #69125