When there are language switches, when we rewind to the start of the
phoneme list we have to reset the phoneme table back.
This avoids some branching that depends on undefined values, caught by
valgrind in the case e.g. of an emoji substitution that contains a
language switch.
Ref #874
This commit implements support for [Totontepec Mixe](https://en.wikipedia.org/wiki/Totontepec_Mixe). The Espeak rules are based on the phonological inventory, orthographic mappings, and phonetic processes described in the "Esbozo fonológico" (phonological outline/sketch) chapter of Verónica Guzmán Guzmán's 2012 master's thesis in Indo American Linguistics awarded by the [Centro de Investigaciones y Estudios Superiores en Antropología Social](https://ciesas.edu.mx/) and *Vocabulario Mixe de Totontepec* (Totontepec Mixe vocabulary), compiled by Alvin Schoenhals and Louise C. Schoenhals and published by the Summer Institute of Linguistics in 1965.
This commit was developed as part of a project for [Computational Linguistics](https://jnw.domains.swarthmore.edu/ling073/syllabus.php) at [Swarthmore College](https://swarthmore.edu). We feel that this language is suitable for merge with "testing" status, but further verification/improvements by native speakers would be very helpful.
co-authored-by: Elizabeth Resendiz <[email protected]>