It looks like we don't create arguments for params arrays during binding. #49602

Consider testing a case like:

using System;

Span<int> M1(Span<int> input, params object[] arr) { return input; }

Span<int> M2()
{
    return M1(stackalloc int[] { 1, 2, 3 });
}

We might want to adjust this step to ensure that all parameters which may factor into escape analysis have arguments. Or just specifically permit a parameter with IsParams == true && Type.TypeKind == TypeKind.Array here, since that's likely the only kind we will miss.
#Resolved

Good catch, thanks.