message: Remove FDisjointLeft check in CRange::PrngExtend()
  FDisjointLeft is a strict superset of the subsequent checks in the if
  case and was therefore redundant. Because the FDisjointLeft() check
  requires querying GPDB and this is in a hot path, removing this provided
  a decent performance improvement.
diff: @@ -630,7 +630,7 @@ CRange::PrngDifferenceLeft
  return this;
  }
  - if (FStartsBefore(prange) && NULL != prange->PdatumLeft())
  + if (NULL != prange->PdatumLeft() && FStartsBefore(prange))
  {
  m_mdid->AddRef();
  @@ -680,7 +680,7 @@ CRange::PrngDifferenceRight
  return this;
  }
  - if (FEndsAfter(prange) && NULL != prange->PdatumRight())
  + if (NULL != prange->PdatumRight() && FEndsAfter(prange))
  {
  m_mdid->AddRef();
  @@ -722,9 +722,9 @@ CRange::PrngExtend
  CRange *prange
  )
  {
  - if (FDisjointLeft(prange) &&
  - m_pcomp->Equals(prange->PdatumLeft(), m_pdatumRight) &&
  - (EriIncluded == prange->EriLeft() || EriIncluded == m_eriRight))
  + if ((EriIncluded == prange->EriLeft() || EriIncluded == m_eriRight)
  + && (m_pcomp->Equals(prange->PdatumLeft(), m_pdatumRight))
  + )
  {
  // ranges are contiguous so combine them into one
  m_mdid->AddRef();
  