Ensure stable sorting order in tools

This eliminates certain surprises with port contents and depot hashes.

tool/depot/mk/common.inc

@@ -30,3 +30,6 @@ EMPTY :=
 # is not empty.
 #
 file_content = $(if $(wildcard $1),$(shell cat $1),)
+
+# Force stable sorting order
+export LC_COLLATE=C

tool/depot/mk/extract.inc

@@ -198,7 +198,7 @@ _check_hash: $(DEPOT_ARCHIVE_DIR).hash checked_recipe_hash_value_exists
 # would otherwise prompt 'cat' to block for standard input.
 #
 HASH_CMD := cd $(DEPOT_ARCHIVE_DIR); \
-            echo | cat `find . -type f | LC_COLLATE=C sort` |  $(HASHSUM) | sed "s/ .*//" \
+            echo | cat `find . -type f | sort` |  $(HASHSUM) | sed "s/ .*//" \
 
 #
 # Generate the hash from the archive content