core: move const tables outside of dispatched code

To avoid duplicates in binaries

modules/core/src/mathfuncs.hpp

@@ -0,0 +1,15 @@
+// This file is part of OpenCV project.
+// It is subject to the license terms in the LICENSE file found in the top-level directory
+// of this distribution and at http://opencv.org/license.html.
+
+#ifndef OPENCV_CORE_SRC_MATHFUNCS_HPP
+#define OPENCV_CORE_SRC_MATHFUNCS_HPP
+
+namespace cv { namespace details {
+const double* getExpTab64f();
+const float*  getExpTab32f();
+const double* getLogTab64f();
+const float*  getLogTab32f();
+}} // namespace
+
+#endif // OPENCV_CORE_SRC_MATHFUNCS_HPP