Allow other compilers
Allow other compilers

To compile with clang:
$ CC=clang make

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