Squashed 'third_party/eigen/' content from commit 61d72f6

Change-Id: Iccc90fa0b55ab44037f018046d2fcffd90d9d025
git-subtree-dir: third_party/eigen
git-subtree-split: 61d72f6383cfa842868c53e30e087b0258177257
diff --git a/failtest/ref_4.cpp b/failtest/ref_4.cpp
new file mode 100644
index 0000000..6c11fa4
--- /dev/null
+++ b/failtest/ref_4.cpp
@@ -0,0 +1,15 @@
+#include "../Eigen/Core"
+
+using namespace Eigen;
+
+void call_ref(Ref<MatrixXf,0,OuterStride<> > a) {}
+
+int main()
+{
+  MatrixXf A(10,10);
+#ifdef EIGEN_SHOULD_FAIL_TO_BUILD
+  call_ref(A.transpose());
+#else
+  call_ref(A);
+#endif
+}