compiler/sparc/subprim: Change LENGTH/LIST to use non-continuable errors.
* There's a small stack of more to be done here, but the use of
continuable errors, while supported at least somewhat by the
runtime, simply isn't supported by the debugger, so there's no
point in using them over the non-continuable errors... And these
are the last two use sites for continuable errors on SPARC.
* There are a few more opportunities for excellence here, but
there are some fiddly little details involved, so they call for