`dst` in memassign_safe should move to next position after `memmove_refs((void**)dst, (void**)src, nptr)`

[awfeequdng]

static inline void memassign_safe(int hasptr, jl_value_t *parent, char *dst, const jl_value_t *src, size_t nb) JL_NOTSAFEPOINT
{
    if (hasptr) {
        // assert that although dst might have some undefined bits, the src heap box should be okay with that
        assert(LLT_ALIGN(nb, sizeof(void*)) == LLT_ALIGN(jl_datatype_size(jl_typeof(src)), sizeof(void*)));
        size_t nptr = nb / sizeof(void*);
        memmove_refs((void**)dst, (void**)src, nptr);
        jl_gc_multi_wb(parent, src);
        src = (jl_value_t*)((char*)src + nptr * sizeof(void*));
        nb -= nptr * sizeof(void*);
    }
    else {
        // src must be a heap box.
        assert(nb == jl_datatype_size(jl_typeof(src)));
        if (nb >= 16) {
            memcpy(dst, jl_assume_aligned(src, 16), nb);
            return;
        }
    }
    memcpy(dst, jl_assume_aligned(src, sizeof(void*)), nb);
}

in memassign_safe, dst must move to the next position after memmove_refs((void**)dst, (void**)src, nptr)，only src is doing that：