message: core(lda): don't perform calculations in constructor
  exceptions from constructor will not cause destructor calls
diff: @@ -903,19 +903,19 @@ public:
  // given in src. This function is a port of the EigenvalueSolver in JAMA,
  // which has been released to public domain by The MathWorks and the
  // National Institute of Standards and Technology (NIST).
  - EigenvalueDecomposition(InputArray src, bool fallbackSymmetric = true) :
  + EigenvalueDecomposition() :
  n(0),
  d(NULL), e(NULL), ort(NULL),
  V(NULL), H(NULL)
  {
  - compute(src, fallbackSymmetric);
  + // nothing
  }
  // This function computes the Eigenvalue Decomposition for a general matrix
  // given in src. This function is a port of the EigenvalueSolver in JAMA,
  // which has been released to public domain by The MathWorks and the
  // National Institute of Standards and Technology (NIST).
  - void compute(InputArray src, bool fallbackSymmetric)
  + void compute(InputArray src, bool fallbackSymmetric = true)
  {
  CV_INSTRUMENT_REGION();
  @@ -970,7 +970,8 @@ void eigenNonSymmetric(InputArray _src, OutputArray _evals, OutputArray _evects)
  else
  src64f = src;
  - EigenvalueDecomposition eigensystem(src64f, false);
  + EigenvalueDecomposition eigensystem;
  + eigensystem.compute(src64f, false);
  // EigenvalueDecomposition returns transposed and non-sorted eigenvalues
  std::vector<double> eigenvalues64f;
  @@ -1146,7 +1147,8 @@ void LDA::lda(InputArrayOfArrays _src, InputArray _lbls) {
  // M = inv(Sw)*Sb
  Mat M;
  gemm(Swi, Sb, 1.0, Mat(), 0.0, M);
  - EigenvalueDecomposition es(M);
  + EigenvalueDecomposition es;
  + es.compute(M);
  _eigenvalues = es.eigenvalues();
  _eigenvectors = es.eigenvectors();
  // reshape eigenvalues, so they are stored by column
  