Function tdesc_intr_void

* Manufacture a void type. Used for gcc-emitted stabs, where the lack of a * type reference implies a reference to a void type. A void *, for example * will be represented by a pointer die without a DW_AT_type. CTF requires * that pointer nodes point to something, so we'll create a void for use as * the target. Note that the DWARF data may already create a void type. Ours * would then be