bump libsass to 3.6.4

asottile · asottile · commit c0c36ecf3340 · 2020-05-01T08:17:13.000-07:00
diff --git a/libsass b/libsass
@@ -1 +1 @@
-Subproject commit e1c16e09b4a953757a15149deaaf28a3fd81dc97
+Subproject commit 8d312a1c91bb7dd22883ebdfc829003f75a82396
