[Libre-soc-dev] post-inc load/store issues

[lkcl]

ah well spotted i must have accidentally deleted those cut/paste
style.  strncpy is... astonishingly, almost laughably short.  6 ops,
2 of which are scalar (mtspr, setvl), only 4 of which are vector.

compared to a scalar strncpy they are near-identical, it is
just the Vectorisation which having included fail-first and
CTR-dec-with-early-exit, these make for drastically shorter
assembler.

oh - the post-increment also helps just as it does in PDP8/11,
CDC 6600, and Motorola 68000.

l.