make fixed size matrices and arrays trivially_copy_constructible and trivially_move_constructible

Eigen/src/Core/Array.h

diff --git a/Eigen/src/Core/Array.h b/Eigen/src/Core/Array.h
index 29c9682..c808b63 100644
--- a/Eigen/src/Core/Array.h
+++ b/Eigen/src/Core/Array.h
@@ -126,9 +126,7 @@
       : Base(internal::constructor_without_unaligned_array_assert()){EIGEN_INITIALIZE_COEFFS_IF_THAT_OPTION_IS_ENABLED}
 #endif
 
-        EIGEN_DEVICE_FUNC Array(Array && other) EIGEN_NOEXCEPT_IF(std::is_nothrow_move_constructible<Scalar>::value)
-      : Base(std::move(other)) {
-  }
+        EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE constexpr Array(Array && other) = default;
   EIGEN_DEVICE_FUNC Array& operator=(Array&& other) EIGEN_NOEXCEPT_IF(std::is_nothrow_move_assignable<Scalar>::value) {
     Base::operator=(std::move(other));
     return *this;
@@ -232,7 +230,7 @@
   }
 
   /** Copy constructor */
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Array(const Array& other) : Base(other) {}
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE constexpr Array(const Array& other) = default;
 
  private:
   struct PrivateType {};

Eigen/src/Core/Matrix.h

diff --git a/Eigen/src/Core/Matrix.h b/Eigen/src/Core/Matrix.h
index 0d8691e..2c64936 100644
--- a/Eigen/src/Core/Matrix.h
+++ b/Eigen/src/Core/Matrix.h
@@ -258,9 +258,7 @@
             internal::constructor_without_unaligned_array_assert)
       : Base(internal::constructor_without_unaligned_array_assert()){EIGEN_INITIALIZE_COEFFS_IF_THAT_OPTION_IS_ENABLED}
 
-        EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE constexpr Matrix(Matrix && other)
-            EIGEN_NOEXCEPT_IF(std::is_nothrow_move_constructible<Scalar>::value)
-      : Base(std::move(other)) {}
+        EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE constexpr Matrix(Matrix && other) = default;
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE constexpr Matrix& operator=(Matrix&& other)
       EIGEN_NOEXCEPT_IF(std::is_nothrow_move_assignable<Scalar>::value) {
     Base::operator=(std::move(other));
@@ -379,7 +377,7 @@
   }
 
   /** \brief Copy constructor */
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Matrix(const Matrix& other) : Base(other) {}
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE constexpr Matrix(const Matrix& other) = default;
 
   /** \brief Copy constructor for generic expressions.
    * \sa MatrixBase::operator=(const EigenBase<OtherDerived>&)

Eigen/src/Core/PlainObjectBase.h

diff --git a/Eigen/src/Core/PlainObjectBase.h b/Eigen/src/Core/PlainObjectBase.h
index 5f846a0..df90318 100644
--- a/Eigen/src/Core/PlainObjectBase.h
+++ b/Eigen/src/Core/PlainObjectBase.h
@@ -485,8 +485,7 @@
   }
 #endif
 
-  EIGEN_DEVICE_FUNC constexpr PlainObjectBase(PlainObjectBase&& other) EIGEN_NOEXCEPT
-      : m_storage(std::move(other.m_storage)) {}
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE constexpr PlainObjectBase(PlainObjectBase&& other) = default;
 
   EIGEN_DEVICE_FUNC constexpr PlainObjectBase& operator=(PlainObjectBase&& other) EIGEN_NOEXCEPT {
     m_storage = std::move(other.m_storage);
@@ -494,8 +493,7 @@
   }
 
   /** Copy constructor */
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE constexpr PlainObjectBase(const PlainObjectBase& other)
-      : Base(), m_storage(other.m_storage) {}
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE constexpr PlainObjectBase(const PlainObjectBase& other) = default;
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE PlainObjectBase(Index size, Index rows, Index cols)
       : m_storage(size, rows, cols) {
     //       EIGEN_INITIALIZE_COEFFS_IF_THAT_OPTION_IS_ENABLED