[fusl] Build libcxx atop fusl

fusl/test/vector.cc

Index: fusl/test/vector.cc
diff --git a/fusl/test/empty_main.c b/fusl/test/vector.cc
similarity index 81%
copy from fusl/test/empty_main.c
copy to fusl/test/vector.cc
index 42d078b358438d7da02576fb31bf1d356199d2a9..77b04a305215b38c1acde7d693940283fbaefb0a 100644
--- a/fusl/test/empty_main.c
+++ b/fusl/test/vector.cc
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <vector>
+
 int main(int argc, char** argv) {
-  return 0;
+  std::vector<int> xs(10);
 }