dev-cpp/folly: skip a test on system-libcxx systems

This test aborts with something about a threading-related assert in
Folly.

Signed-off-by: sin-ack <sin-ack@protonmail.com>
Closes: https://github.com/gentoo/gentoo/pull/39437
Signed-off-by: Sam James <sam@gentoo.org>

dev-cpp/folly/folly-2024.11.04.00-r2.ebuild

@@ -13,7 +13,7 @@ EAPI=8
 # dev-cpp/wangle
 # dev-util/watchman
 
-inherit flag-o-matic cmake
+inherit flag-o-matic cmake toolchain-funcs
 
 DESCRIPTION="An open-source C++ library developed and used at Facebook"
 HOMEPAGE="https://github.com/facebook/folly"
@@ -101,5 +101,13 @@ src_test() {
 		)
 	fi
 
+	if [[ $(tc-get-cxx-stdlib) == libc++ ]]; then
+		CMAKE_SKIP_TESTS+=(
+			# Aborts with libc++.
+			# https://github.com/facebook/folly/issues/2345
+			buffered_atomic_test.BufferedAtomic.singleThreadUnguardedAccess
+		)
+	fi
+
 	cmake_src_test
 }