Follow-up from "Various Rich SIMD Reconstruction improvements"

The following discussion from !814 (merged) should be addressed:

• @cattanem started a discussion: (+2 comments)

  @jonrob this breaks compilation with clang: https://lhcb-nightlies.cern.ch/logs/build/nightly/lhcb-clang-test/798/x86_64-centos7-clang50-opt/Rec/

I've pushed what I really hope is a fix this time to !818 (merged)

Fix confirmed

closed

mentioned in commit 0c0d232f

mentioned in commit d07665b8