[VecOps] Add missing include for c++11 builds
[VecOps] Add missing include for c++11 builds

olifre/root,olifre/root,olifre/root,karies/root,olifre/root,karies/root,root-mirror/root,olifre/root,root-mirror/root,karies/root,karies/root,root-mirror/root,root-mirror/root,karies/root,root-mirror/root,root-mirror/root,olifre/root,olifre/root,olifre/root,root-mirror/root,karies/root,root-mirror/root,olifre/root,root-mirror/root,olifre/root,karies/root,karies/root,karies/root,karies/root,root-mirror/root,karies/root,olifre/root,root-mirror/root