[libc++] Fix CMake cache for the hardening with ABI breaks CI (#105864)

We were incorrectly only enabling _LIBCPP_ABI_BOUNDED_ITERATORS, without
enabling bounded iterators in string and vector.

Author: ldionne

libcxx/cmake/caches/Generic-hardening-mode-fast-with-abi-breaks.cmake

@@ -1,4 +1,2 @@
 set(LIBCXX_HARDENING_MODE "fast" CACHE STRING "")
-set(LIBCXX_ABI_DEFINES "_LIBCPP_ABI_BOUNDED_ITERATORS" CACHE STRING "")
-set(LIBCXX_ABI_DEFINES "_LIBCPP_ABI_BOUNDED_ITERATORS_IN_STRING" CACHE STRING "")
-set(LIBCXX_ABI_DEFINES "_LIBCPP_ABI_BOUNDED_ITERATORS_IN_VECTOR" CACHE STRING "")
+set(LIBCXX_ABI_DEFINES "_LIBCPP_ABI_BOUNDED_ITERATORS;_LIBCPP_ABI_BOUNDED_ITERATORS_IN_STRING;_LIBCPP_ABI_BOUNDED_ITERATORS_IN_VECTOR" CACHE STRING "")

libcxx/utils/ci/run-buildbot

@@ -417,7 +417,7 @@ generic-hardening-mode-fast-with-abi-breaks)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-hardening-mode-fast-with-abi-breaks.cmake"
     check-runtimes
-    check-abi-list
+    # Not checking ABI list since we purposefully enable ABI breaking changes
 ;;
 generic-hardening-mode-extensive)
     clean