* optimization in the 8087/80287 version of fpc_arctan_real(): when calculating
  arctan([-]1/d), use fxch to swap the two arguments, instead of using fdivr,
  since fpatan can do the division for free



git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@26227 3ad0048d-3df7-0310-abae-a5850022a9f2