Support Slices stdlib

[PXshadow]

Stdlib slices is a new go 1.21.0 package that uses an extensive amount of generics. It is also being used in the internals now of sort.

Here is a test case that is currently not working with the latest go2hx version:

func Min[S ~[]E, E cmp.Ordered](x S) E {
	if len(x) < 1 {
		panic("slices.Min: empty list")
	}
	m := x[0]
	for i := 1; i < len(x); i++ {
		m = min(m, x[i])
	}
	return m
}

The haxe version is missing the E typeParam.

macro function min<S>(_x:haxe.macro.Expr.ExprOf<S>):haxe.macro.Expr.ExprOf<E>;

I will add commits in connection to this issue.