Bug 958 - Allow testing specific blocking sizes
Bug 958 - Allow testing specific blocking sizes

This is only a debugging/testing patch. It allows testing specific
product blocking sizes, typically to study the impact on performance.

Example usage:

int testk, testm, testn;
#define EIGEN_TEST_SPECIFIC_BLOCKING_SIZES
#define EIGEN_TEST_SPECIFIC_BLOCKING_SIZE_K testk
#define EIGEN_TEST_SPECIFIC_BLOCKING_SIZE_M testm
#define EIGEN_TEST_SPECIFIC_BLOCKING_SIZE_N testn
#include <Eigen/Core>

pthulhu/eigen,pthulhu/eigen,pthulhu/eigen,pthulhu/eigen,pthulhu/eigen