Fix PPC rand and other failures.

test/array_for_matrix.cpp

diff --git a/test/array_for_matrix.cpp b/test/array_for_matrix.cpp
index afe6894..6d7d0dd 100644
--- a/test/array_for_matrix.cpp
+++ b/test/array_for_matrix.cpp
@@ -19,12 +19,18 @@
   Index cols = m.cols();
 
   MatrixType m1 = MatrixType::Random(rows, cols), m2 = MatrixType::Random(rows, cols), m3(rows, cols);
-
   ColVectorType cv1 = ColVectorType::Random(rows);
   RowVectorType rv1 = RowVectorType::Random(cols);
 
   Scalar s1 = internal::random<Scalar>(), s2 = internal::random<Scalar>();
 
+  // Prevent overflows for integer types.
+  if (Eigen::NumTraits<Scalar>::IsInteger) {
+    constexpr Scalar kMaxVal = Scalar(10000);
+    m1.array() = m1.array() - kMaxVal * (m1.array() / kMaxVal);
+    m2.array() = m2.array() - kMaxVal * (m2.array() / kMaxVal);
+  }
+
   // scalar addition
   VERIFY_IS_APPROX(m1.array() + s1, s1 + m1.array());
   VERIFY_IS_APPROX((m1.array() + s1).matrix(), MatrixType::Constant(rows, cols, s1) + m1);