true if this value has the structure of a D dynamic array.
A D dynamic array has two fields: length (or _length) and ptr (or _ptr). This method checks for that field pair in both tuple values and stringified GDB summaries (strings that start with `{`).
Plain MI string values that lack the length/ptr structure return false, even though GDB may already represent them as character arrays. Use kind == MiValueKind.STRING to test for plain strings.