Fix bug #480: workaround the Android NDK defining isfinite as a macro

Eigen/src/Cholesky/LDLT.h

@@ -370,7 +370,7 @@ template<> struct ldlt_inplace<Lower>
     for (Index j = 0; j < size; j++)
     {
       // Check for termination due to an original decomposition of low-rank
-      if (!isfinite(alpha))
+      if (!(isfinite)(alpha))
         break;
 
       // Update the diagonal terms

Eigen/src/Core/MathFunctions.h

@@ -845,7 +845,7 @@ template<> struct scalar_fuzzy_impl<bool>
 
 // std::isfinite is non standard, so let's define our own version,
 // even though it is not very efficient.
-template<typename T> bool isfinite(const T& x)
+template<typename T> bool (isfinite)(const T& x)
 {
   return x<NumTraits<T>::highest() && x>NumTraits<T>::lowest();
 }