Fix -Wimplicit-int, -Wstrict-prototypes
https://github.com/garrigue/labltk/commit/8f69b154d719d532b18981add91ce445668a2fac
--- config/auto-aux/hasgot.orig
+++ config/auto-aux/hasgot
@@ -31,7 +31,7 @@ while : ; do
 done
 
 (for f in $*; do echo "int $f();"; done
- echo "int main() {"
+ echo "int main(void) {"
  for f in $*; do echo "  $f();"; done
  echo "}") >> hasgot.c
 
--- config/auto-aux/tclversion.c.orig
+++ config/auto-aux/tclversion.c
@@ -18,7 +18,7 @@
 #include <tcl.h>
 #include <tk.h>
 
-main ()
+int main (void)
 {
     puts(TCL_VERSION);
 }