Merged in mfigurnov/eigen/fix-bessel (pull request PR-404)

Fix compilation of special functions without C99 math.

unsupported/Eigen/src/SpecialFunctions/SpecialFunctionsImpl.h

diff --git a/unsupported/Eigen/src/SpecialFunctions/SpecialFunctionsImpl.h b/unsupported/Eigen/src/SpecialFunctions/SpecialFunctionsImpl.h
index 6c7ac3f..293b059 100644
--- a/unsupported/Eigen/src/SpecialFunctions/SpecialFunctionsImpl.h
+++ b/unsupported/Eigen/src/SpecialFunctions/SpecialFunctionsImpl.h
@@ -1574,6 +1574,8 @@
   }
 };
 
+#endif  // EIGEN_HAS_C99_MATH
+
 /****************************************************************************
  * Implementation of Bessel function, based on Cephes                       *
  ****************************************************************************/
@@ -1902,8 +1904,6 @@
   }
 };
 
-#endif  // EIGEN_HAS_C99_MATH
-
 }  // end namespace internal
 
 namespace numext {

unsupported/test/special_functions.cpp

diff --git a/unsupported/test/special_functions.cpp b/unsupported/test/special_functions.cpp
index 48d0db9..0729dd4 100644
--- a/unsupported/test/special_functions.cpp
+++ b/unsupported/test/special_functions.cpp
@@ -335,6 +335,7 @@
         ArrayType test = betainc(a, b + one, x) + eps;
         verify_component_wise(test, expected););
   }
+#endif  // EIGEN_HAS_C99_MATH
 
   // Test Bessel function i0e. Reference results obtained with SciPy.
   {
@@ -375,7 +376,6 @@
     CALL_SUBTEST(res = i1e(x);
                  verify_component_wise(res, expected););
   }
-#endif
 }
 
 void test_special_functions()