debug split: move check for enabling debug symbol splitting from functions.in into Build-Pkg

The check will be run right after the postinstall hook and before
creating the flist.

lib/functions.in

@@ -1231,11 +1231,6 @@ build_this_package() {
 			done
 		fi
 
-		# split debug symbols
-		if [ "$SDECFG_DEBUG_SPLIT" = 1 ] && ! atstage toolchain; then
-			split_debug_files
-		fi
-
 		if [ "$createdocs" != 0 ]; then
 			if [ ! -e $root$docdir ]; then
 				mkdir -p $docdir

scripts/Build-Pkg

@@ -652,6 +652,11 @@ abort() {
 
 	hook_eval postinstall
 
+	# split debug symbols
+	if [ "$SDECFG_DEBUG_SPLIT" = 1 ] && ! atstage toolchain; then
+		split_debug_files
+	fi
+
 	echo "Creating file list and doing final adaptions ... "
 	#
 	cd $xroot/