Handle BSD checksum utilities

The BSDs have different checksum utilities than GNU systems do. If we
don't see the GNU checksum utilities installed, use the BSD ones, as
their output is compatible enough.

Addresses part of phpGH-14688.

scripts/dev/gen_verify_stub

@@ -1,5 +1,9 @@
 #!/bin/bash
 
+# Handle GNU vs. BSD checksum utilities
+sha256sum="$(which sha256sum)"
+sha256sum="${sha256sum:-$(which shasum) -a 256}"
+
 if [ "x$1" == "x" ]
 then
 	echo "Usage: $0 <version> [email]"
@@ -41,7 +45,7 @@ done
 for TARBALL in "$PHPROOT/php-$RELEASE_VER.tar.bz2" "$PHPROOT/php-$RELEASE_VER.tar.gz" "$PHPROOT/php-$RELEASE_VER.tar.xz"
 do
 	basename $TARBALL
-	echo "SHA256 hash: `sha256sum $TARBALL | cut -d' ' -f1`";
+	echo "SHA256 hash: `$sha256sum $TARBALL | cut -d' ' -f1`";
 	echo PGP signature:
 	cat $TARBALL.asc
 	echo -e "\n"

scripts/dev/makedist

@@ -9,6 +9,10 @@
 tar="$(which gtar)"
 tar="${tar:-$(which tar)}"
 
+# Handle GNU vs. BSD checksum utilities
+md5sum="$(which md5sum)"
+md5sum="${md5sum:-$(which md5)}"
+
 if [[ $($tar --version) == *"bsdtar"* ]]; then
   echo "Found bsdtar at $tar, but this script needs GNU tar."
   exit 1
@@ -181,23 +185,23 @@ rm -rf "$prefix" "$prefix".tar.*
 
 echo "makedist: Creating $prefix.tar.gz archive."
 gzip -9 -k "$prefix".tar || exit 6
-md5sum "$prefix".tar.gz
+"$md5sum" "$prefix".tar.gz
 gzip -t "$prefix".tar.gz
 
 sync
 sleep 2
 
 echo "makedist: Creating $prefix.tar.bz2 archive."
 bzip2 -9 -k $prefix.tar || exit 7
-md5sum $prefix.tar.bz2
+"$md5sum" $prefix.tar.bz2
 bzip2 -t $prefix.tar.bz2
 
 sync
 sleep 2
 
 echo "makedist: Creating $prefix.tar.xz archive."
 xz -9 -k "$prefix".tar || exit 9
-md5sum "$prefix".tar.xz
+"$md5sum" "$prefix".tar.xz
 xz -t "$prefix".tar.xz
 
 echo ""