development/z88dk: Fix -current build.

Signed-off-by: B. Watson <yalhcru@gmail.com>

Signed-off-by: Willy Sudiarto Raharjo <willysr@slackbuilds.org>

development/z88dk/z88dk.SlackBuild

@@ -12,6 +12,8 @@
 # of a release. I'll admit, my motivation for that will be that I want
 # to have a C compiler that targets Pac-Man arcade hardware (the 1.99B
 # release doesn't, current git does).
+# 20210907 bkw: the above TODO still stands, but I don't have time to do
+# it right now (gearing up for 15.0 release).
 
 cd $(dirname $0) ; CWD=$(pwd)
 
@@ -29,9 +31,6 @@ if [ -z "$ARCH" ]; then
   esac
 fi
 
-# If the variable PRINT_PACKAGE_NAME is set, then this script will report what
-# the name of the created package would be, and then exit. This information
-# could be useful to other scripts.
 if [ ! -z "${PRINT_PACKAGE_NAME}" ]; then
   echo "$PRGNAM-$VERSION-$ARCH-$BUILD$TAG.$PKGTYPE"
   exit 0
@@ -72,6 +71,7 @@ find . -type d   -print0 | xargs -0 chmod 0755
 chmod +x *.sh
 
 # Sneaky ways to inject CFLAGS.
+SLKCFLAGS+=" -fcommon"
 sed -i "s/CC=gcc/CC='gcc $SLKCFLAGS'/" build.sh
 export CXX="g++ $SLKCFLAGS"