client almost builds

vendor/cryptopp/TestPrograms/test_cxx11_staticinit.cpp

@@ -0,0 +1,11 @@
+// https://en.cppreference.com/w/cpp/feature_test
+// Apple bug https://bugs.llvm.org/show_bug.cgi?id=47012.
+int main(int argc, char* argv[])
+{
+#if __cpp_threadsafe_static_init >= 200806L
+    int x[1];
+#else
+    int x[-1];
+#endif
+    return 0;
+}