Add const_negate() which negates a Const node. Implement - const - (a - b) -> (b - a) + -const - const1 - (a * const2) -> (a * -const2) + -const1
Add const_negate() which negates a Const node.
Implement
- const - (a - b) -> (b - a) + -const
- const1 - (a * const2) -> (a * -const2) + -const1

[r15779]

MatzeB/libfirm,8l/libfirm,davidgiven/libfirm,8l/libfirm,MatzeB/libfirm,jonashaag/libfirm,killbug2004/libfirm,libfirm/libfirm,killbug2004/libfirm,jonashaag/libfirm,libfirm/libfirm,libfirm/libfirm,davidgiven/libfirm,MatzeB/libfirm,jonashaag/libfirm,killbug2004/libfirm,davidgiven/libfirm,MatzeB/libfirm,jonashaag/libfirm,jonashaag/libfirm,killbug2004/libfirm,libfirm/libfirm,MatzeB/libfirm,8l/libfirm,8l/libfirm,davidgiven/libfirm,8l/libfirm,killbug2004/libfirm,jonashaag/libfirm,davidgiven/libfirm,killbug2004/libfirm,MatzeB/libfirm,davidgiven/libfirm,8l/libfirm,libfirm/libfirm,8l/libfirm,jonashaag/libfirm,killbug2004/libfirm,MatzeB/libfirm,davidgiven/libfirm