dsp_orig in u-dialect.c => unsigned
dsp_orig in u-dialect.c => unsigned

While it might not always be kept this way, the DSP is -1 when it has
no items on the stack.  So it is a signed REBINT vs. unsigned REBCNT.

giuliolunati/ren-c,kealist/ren-c,codebybrett/ren-c,giuliolunati/ren-c,hostilefork/rebol,hostilefork/rebol,hostilefork/rebol,draegtun/ren-c,hostilefork/rebol,draegtun/ren-c,kealist/ren-c,giuliolunati/ren-c,codebybrett/ren-c,rgchris/ren-c,hostilefork/rebol,rgchris/ren-c,kealist/ren-c,rgchris/ren-c,codebybrett/ren-c,draegtun/ren-c,giuliolunati/ren-c,giuliolunati/ren-c,draegtun/ren-c,kealist/ren-c,codebybrett/ren-c,codebybrett/ren-c,rgchris/ren-c,draegtun/ren-c,hostilefork/rebol,rgchris/ren-c,kealist/ren-c,draegtun/ren-c,kealist/ren-c,codebybrett/ren-c