[roll] Roll fuchsia [superproject] Roll llvm-project/libc [libc] Remove _Exit proxy func header and use LIBC_NAMESPACE::_Exit in tests (#114904)

This improves/fixes this pr
llvm/llvm-project#114718. In this PR we removed
the _Exit proxy func because it was not needed. Instead we used
`LIBC_NAMESPACE::_Exit`

GitOrigin-RevId: 0b99129c6f14da2553ea6702291f56ef858a1aac
Original-Revision: 7a1d7e7fcd4655b6f2b7efe120e442734a8d20bd
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1153254
Original-Revision: 03a718a6745a6fcd6aed461d69e6f1eaf4a04740
Change-Id: Ia6da8c64fd00a2a008200142f80a69cb9bd6a672

Author: global-integration-roller

stem

@@ -11,7 +11,7 @@
              githooks="integration/git-hooks"
              remote="https://fuchsia.googlesource.com/fuchsia"
              gerrithost="https://fuchsia-review.googlesource.com"
-             revision="8ec44c1d2e7bf1225e4164c3eb636ce91d97cb21"/>
+             revision="03a718a6745a6fcd6aed461d69e6f1eaf4a04740"/>
   </projects>
   <hooks>
     <hook name="install-environment"