Even though letters ă, c̆, ĕ, ğ, ĭ, k̆, m̆, n̆, ŏ, p̆, r̆, t̆, ŭ, v̆, x̆, y̆ are included in the Default font, the standalone breve (˘) isn't

All accented letters have their default look, but if the breve doesn't mutate anything, it isn't

Relates to MC-193223 and MC-169319.