FindMatlab: Fix compilation error in one specific test configuration.

`matlab_wrapper2.cpp` failed to compile in one specific test configuration.
I've copied an odd workaround from `matlab_wrapper1.cpp`, which doesn't fail
to compile. I presume this workaround was meant to address this issue, but
can't verify this locally.

Tests/FindMatlab/matlab_wrapper2.cpp

@@ -1,3 +1,9 @@
+
+// simple workaround to some compiler specific problems
+// see
+// http://stackoverflow.com/questions/22367516/mex-compile-error-unknown-type-name-char16-t/23281916#23281916
+#include <algorithm>
+
 #include "mex.h"
 
 // This test uses the new complex-interleaved C API (R2018a and newer)