Enbase fixes for input zero length strings
Enbase fixes for input zero length strings

(There are actually a bunch more things in this category, which I
am not currently focusing on getting in ATM.  But this one just got
triggered while I was building hostilefork.com after changing the call
stack implementation.)

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