JIT: Assertion failed 'isValidGeneralDatasize(size)' during 'Generate code'

[jakobbotsch]

using System;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;

public static unsafe class Program
{
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    private static ref byte GetNonNullPinnableReference(Span<byte> buffer)
    {
        return ref buffer.Length != 0 ? ref MemoryMarshal.GetReference(buffer) : ref Unsafe.AsRef<byte>((void*)1);
    }

    [MethodImpl(MethodImplOptions.NoInlining)]
    private static int Consume(byte* p, int length) => p is null ? -1 : length;

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    private static int Pin(Span<byte> destination)
    {
        fixed (byte* p = &GetNonNullPinnableReference(destination))
        {
            int status = Consume(p, destination.Length);

            if (status != 0)
            {
                throw new InvalidOperationException();
            }

            return status;
        }
    }

    public static int Main()
    {
        int result = Pin(default);
        Console.WriteLine($"Pin(default) = {result}");
        return result == 0 ? 100 : 1;
    }
}

src\coreclr\jit\emitarm64.cpp:3025
Assertion failed 'isValidGeneralDatasize(size)' in 'Program:Main():int' during 'Generate code' (IL size 65; hash 0xd9b8a0c8; FullOpts)

Reproduces only with crossgen2/ilc.

I hit this in a less-contrived example in #131538.

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