target-ppc: Add ISA2.06 Float to Integer Instructions

target-ppc: Add ISA2.06 Float to Integer Instructions

This patch adds the four floating point to integer conversion instructions
introduced by Power ISA V2.06:

  - Floating Convert to Integer Word Unsigned (fctiwu)
  - Floating Convert to Integer Word Unsigned with Round Toward
    Zero (fctiwuz)
  - Floating Convert to Integer Doubleword Unsigned (fctidu)
  - Floating Convert to Integer Doubleword Unsigned with Round
    Toward Zero (fctiduz)

A common macro is developed to eliminate repetitious code.  Existing instructions
are also refactoried to use this macro (fctiw, fctiwz, fctid, fctidz).

Signed-off-by: Tom Musta <tommusta@gmail.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Alexander Graf <agraf@suse.de>