Update stdsimd to undo an accidental stabilization

alexcrichton · alexcrichton · commit ec4aaf164083 · 2018-07-19T07:01:37.000-07:00
Closes #52403
diff --git a/src/stdsimd b/src/stdsimd
@@ -1 +1 @@
-Subproject commit 886ff388fbbe8798e292431d824a5ff3c3458f4d
+Subproject commit 85208cf0978dbdf5630fea1d9e4a6a7b217f2acd
