Fix imHereBecauseOfCrayCompiler bug

Created by: jgphpc

This does not look too good:

grep imHereBecauseOfCrayCompilerO2Bug -r include/*

include/sph/density.hpp:    std::vector<T> imHereBecauseOfCrayCompilerO2Bug(4, 10);
include/sph/momentumAndEnergyIAD.hpp:    std::vector<T> imHereBecauseOfCrayCompilerO2Bug(4, 10);
include/sph/findNeighbors.hpp:    std::vector<T> imHereBecauseOfCrayCompilerO2Bug(4, 10);
include/sph/IAD.hpp:    std::vector<T> imHereBecauseOfCrayCompilerO2Bug(4, 10);