[roll] Roll fuchsia [kernel][rust] Rust percpu struct

Defines a 'native' Rust PerCpu struct, albeit with opaque types for
most of the members. bindgen is used to validate the size and layout
equivalence with C++, and the simple accessor methods are implemented
using FFI.

Original-Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1819212
Original-Original-Revision: 11a9daf6ab4f17f724f22b6be12796f842ce0293
GitOrigin-RevId: add6373ad2b8985e4a55f3a3b751ac32c6cae0f1
Change-Id: Idc63c2660050ed0aed8689b07f315617b32a32db
Reviewed-on: https://fuchsia-review.googlesource.com/c/integration/+/1823289
Cr-Commit-Position: refs/heads/main@{#201940}

stem

diff --git a/stem b/stem
index 8a45873..78ebcac 100644
--- a/stem
+++ b/stem
@@ -8,6 +8,6 @@
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-            revision="e485467a32922e19418a5f0904d60292b1d1628d"/>
+            revision="11a9daf6ab4f17f724f22b6be12796f842ce0293"/>
   </imports>
 </manifest>