astr_vadd_at() not thread safe
As astr_vadd_at() uses single internal buffer for all calls, it's not thread safe. I've not yet investigated if it's ever used in a context where we expect thread safety.
For S2_6 too.
As astr_vadd_at() uses single internal buffer for all calls, it's not thread safe. I've not yet investigated if it's ever used in a context where we expect thread safety.