with old gcc (bug 89), only include iostream in debug mode
with old gcc (bug 89), only include iostream in debug mode

pasuka/eigen,ritsu1228/eigen,pasuka/eigen,ritsu1228/eigen,toastedcrumpets/eigen,TSC21/Eigen,Zefz/eigen,ROCmSoftwarePlatform/hipeigen,toastedcrumpets/eigen,ritsu1228/eigen,Zefz/eigen,ritsu1228/eigen,Zefz/eigen,toastedcrumpets/eigen,pasuka/eigen,ritsu1228/eigen,toastedcrumpets/eigen,TSC21/Eigen,TSC21/Eigen,ROCmSoftwarePlatform/hipeigen,pasuka/eigen,ROCmSoftwarePlatform/hipeigen,pasuka/eigen,ROCmSoftwarePlatform/hipeigen,Zefz/eigen,TSC21/Eigen