[m4] Explicitly casting args to all isxxxxx() functions to unsigned char as per RT#40865
[m4] Explicitly casting args to all isxxxxx() functions to unsigned char as
per RT#40865


git-svn-id: 25691d43496b77c53f0b494379003863a981bfc4@20092 d31e2699-5ff4-0310-a27c-f18f2fbe73fe

bschmalhofer/m4