InitializeArray intrinsic must always be expanded

[MichalStrehovsky]

I'm hitting the NO_WAY("JIT must expand the intrinsic!"); in Microsoft.CSharp assembly. This is in the same spirit as dotnet/coreclr#9948.

To repro, compile a hello world app with

--singlemethodtypename Microsoft.CSharp.RuntimeBinder.Semantics.ExpressionBinder,Microsoft.CSharp --singlemethodname .cctor --codegenopt NGenDump=*

From the looks, this is caused by a stack spill somewhere else than ldtoken. This doesn't repro if -O is passed.

NGenDump:
ngendump.txt

[sandreenko]

Fixed in dotnet/CoreCLR#14301. CoreRT RyuJit version is not updated yet.