Ship `llvm-cxxfilt` in the toolchain.

Originally done for rdar://problem/57155465.

rdar://76602859

Differential Revision: https://reviews.llvm.org/D100405

GitOrigin-RevId: 4c0bc69490a57f2f8f9ede948e6d66cc0900879a
diff --git a/cmake/caches/Apple-stage2.cmake b/cmake/caches/Apple-stage2.cmake
index d347ffc..a2eb42e 100644
--- a/cmake/caches/Apple-stage2.cmake
+++ b/cmake/caches/Apple-stage2.cmake
@@ -56,6 +56,7 @@
   llvm-objdump
   llvm-nm
   llvm-size
+  llvm-cxxfilt
   llvm-config
   CACHE STRING "")