Functions do not appear to exist:
extern MagWindow *CmdGetRootBox();
extern void CmdAddSlop();
extern void CmdDoMacro();
K&R obsolete syntax removal for C23 compatibility series
This commit makes the code (mostly) C99-compatible, enabling to compile
it without the -Wno-error=implicit-function-declaration flag. This
way, Magic becomes usable on arm64 architectures, specifically on Apple
computers with M1/M2 SoC.
Darryl L. Miles
Alessandro De Laurenzis
Tim Edwards