+ enabled the use of the DIV/IDIV instruction for 16-bit div/mod on i8086
* ti8086.moddivnode.pass_generate_code: use cg.a_op_const_reg, instead of
  emit_const_reg, in order to support generating plain 8086/8088 code
  (shr/shl/sar reg,const is 186+ if const is >= 2).



git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@26063 3ad0048d-3df7-0310-abae-a5850022a9f2