[roll] Roll fuchsia [superproject] Roll llvm-project/libc 8484530..250f718 (2 commits)

250f718 [libc] Fix some tests on NVPTX due to insufficient stack size
4f459f6 [libc][NFC] Simplify LibcTest and trim down string allocations

GitOrigin-RevId: 859841116f0a7ec3598d6cb6bdeef772a80f9cf2
Roller-URL: https://ci.chromium.org/b/8778700081017697345
CQ-Do-Not-Cancel-Tryjobs: true
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/869576
Original-Revision: a1c0958009b1bcd559c4d9bd6487afab5b5f4819
Change-Id: I6ffbe24bb2f9d88f013f748e11c7fe782c88ca03
diff --git a/stem b/stem
index ed913d2..b957858 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="5b37ff60222d6480677188e7f26b6a1ca10b0bd3"/>
+             revision="a1c0958009b1bcd559c4d9bd6487afab5b5f4819"/>
   </projects>
   <hooks>
     <hook name="install-environment"