roslyn: Type `T[]*` reports parser error

Version Used:

VS 17.5p1

Steps to Reproduce:

Type a code snippet that uses int[]*:

#pragma warning disable CS8500

static unsafe long IterateBits(long* array, int length, int* @out)
{
    var baseVec = Vector256.Create(-1);
    var incVec = Vector256.Create(64);
    var add8 = Vector256.Create(8);
    var initOut = @out;

    for (var i = 0; i < length; i++)
    {
        var w = array[i];
        if (w == 0)
        {
            baseVec += incVec;
        }
        else
        {
            for (var k = 0; k < 4; k++)
            {
                var byteA = (byte)w;
                var byteB = (byte)(w >> 8);
                w >>= 16;

//                       ↓ here
                fixed (int[]* pVt = BitPosTable)
//                     ~~~~~~
                fixed (int* pByteA = pVt[byteA], pByteB = pVt[byteB])
                {
                    var vecA = Vector256.Load(pByteA);
                    var vecB = Vector256.Load(pByteB);
                    var advanceA = LengthTable[byteA];
                    var advanceB = LengthTable[byteB];
                    vecA = baseVec + vecA;
                    baseVec += add8;
                    vecB = baseVec + vecB;
                    baseVec += add8;

                    Vector256.Store(vecA, @out);
                    @out += advanceA;
                    Vector256.Store(vecB, @out);
                    @out += advanceB;
                }
            }
        }
    }

    return @out - initOut;
}

sharplab

Expected Behavior:

No parser error on int[]*: C# 11 allows managed-typed pointers.

Actual Behavior:

It seems that C# syntax parser cannot correctly handle the expression int[]*; we should add an extra but unnecessary token ? to make parser behave well: int[]?*.