Compile the following program and run:

static unsafe void Main(string[] args)
{
    Unsafe.InitBlock(null, 0, 1000);
}

CoreCLR:

Unhandled exception. System.NullReferenceException: Object reference not set to an instance of an object.

NativeAOT:

no exception, exits.

I assume this is what these comments mean:

(while CoreCLR wraps memset/memcpy calls into non-inlineable/without tail calls helpers)