Bump snmalloc-sys/snmalloc from ee470c5 to 8840b38

dependabot-preview[bot] · SchrodingerZhu · commit 3d63731ca5d2 · 2021-02-25T16:08:13.000+08:00
Bumps [snmalloc-sys/snmalloc](https://github.com/microsoft/snmalloc) from `ee470c5` to `8840b38`. - [Release notes](https://github.com/microsoft/snmalloc/releases) - [Commits](microsoft/snmalloc@ee470c5...8840b38) Signed-off-by: dependabot-preview[bot] <support@dependabot.com>
diff --git a/snmalloc-sys/snmalloc b/snmalloc-sys/snmalloc
@@ -1 +1 @@
-Subproject commit ee470c535e258d93590488a4e1266bbe24dc90f1
+Subproject commit 8840b386bc9af30503a7e3afbaa570b2dde87af7
