minor, allow _popcntX() routine only when it comes from intel
chore, conditionalise on available compiler support in glep_simd_dsptch_nfo() as well (not just CPU features)
Merge branch 'tool/glep'

* tool/glep:
  chore, conditionalise on available compiler support in glep_simd_dsptch_nfo() as well (not just CPU features)
  minor, allow _popcntX() routine only when it comes from intel