[roll] Roll fuchsia [kernel][arm64][mmu] When querying a page, tighten asserts for invalid PTEs

While drilling through the page tables, assert that if the page is
marked invalid (bit 0 == 0) that the rest of the pte is also zero, since
currently nothing is stored in unused entries. This should help catch
random corruptions.

Previously the assert would happen later but not print the full value.

Original-Bug: 135207
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/931524
Original-Revision: bf2b53a8ccd6edb1342bcf14f0b3ccad2ab34015
GitOrigin-RevId: 21e03bc9a5876e9cf5035078964da3e7f3c44655
Change-Id: I315fe6e8167746cf7aa6e6ec6ba7b68d493f44ce
diff --git a/stem b/stem
index 00e9b2f..adbab76 100644
--- a/stem
+++ b/stem
@@ -11,7 +11,7 @@
              githooks="integration/git-hooks"
              remote="https://fuchsia.googlesource.com/fuchsia"
              gerrithost="https://fuchsia-review.googlesource.com"
-             revision="ae0eadc359b30797083b31b19751e829a99b406b"/>
+             revision="bf2b53a8ccd6edb1342bcf14f0b3ccad2ab34015"/>
   </projects>
   <hooks>
     <hook name="install-environment"