Update Eigen to the latest stable release, 3.2.2

./Eigen/src/Core/util/NonMPL2.h is left untouched, so that
usage of non MPL2 code is disabled.

Change-Id: I86fc9257b3c30d0ca15b268d4ef07bf038bba7ca
diff --git a/test/selfadjoint.cpp b/test/selfadjoint.cpp
index 6d3ec65..76dab6d 100644
--- a/test/selfadjoint.cpp
+++ b/test/selfadjoint.cpp
@@ -16,7 +16,6 @@
 {
   typedef typename MatrixType::Index Index;
   typedef typename MatrixType::Scalar Scalar;
-  typedef typename NumTraits<Scalar>::Real RealScalar;
 
   Index rows = m.rows();
   Index cols = m.cols();
@@ -47,7 +46,7 @@
 {
   for(int i = 0; i < g_repeat ; i++)
   {
-    int s = internal::random<int>(1,EIGEN_TEST_MAX_SIZE); EIGEN_UNUSED_VARIABLE(s);
+    int s = internal::random<int>(1,EIGEN_TEST_MAX_SIZE);
 
     CALL_SUBTEST_1( selfadjoint(Matrix<float, 1, 1>()) );
     CALL_SUBTEST_2( selfadjoint(Matrix<float, 2, 2>()) );
@@ -55,7 +54,7 @@
     CALL_SUBTEST_4( selfadjoint(MatrixXcd(s,s)) );
     CALL_SUBTEST_5( selfadjoint(Matrix<float,Dynamic,Dynamic,RowMajor>(s, s)) );
     
-    EIGEN_UNUSED_VARIABLE(s)
+    TEST_SET_BUT_UNUSED_VARIABLE(s)
   }
   
   CALL_SUBTEST_1( bug_159() );