cleanup ircons code; add current_ir_graph independent construction bits; new_ir_graph does not set current_ir_graph anymore

[r28042]

[r28037]

[r28032]

[r28030]

[r28021]

[r28020]

differentiate between Bad and Deleted (because of exchange) nodes, this avoid some invalid memory accesses when trying to get irg from a Bad node

[r28019]

[r28018]

[r27979]

[r27968]

[r27967]

a normalisation which shrinks values on the right shift operand because of modulo_shift behaviour. As a nice side-effect this simplifies the Rotl matcher

[r27954]

[r27953]

[r27948]

use operands_are_normalized when permuting Not operations on Xor inputs to avoid commutative normalisation turning it back

[r27947]

[r27945]

[r27944]

backend is responsible for defining what lowering operations need to be performed => so the logical thing is to use a backend callback for performing lowerings

[r27938]

[r27913]

bring back Carry and Borrow (firm_decomp apparently uses it) and add a note that the backends don't support them

[r27849]

[r27836]

[r27833]

[r27831]

[r27813]

[r27762]

combo, just combo's evaluators must be synced between compute_Cmp() and
compute_Proj_Cmp().

[r27410]

[r27394]

[r27346]

[r27328]

now, a 0 means that a 0 is set for sure

[r27313]

[r27300]

- cleanup ir_spec generation a bit

[r27251]

- removed useless Id-node creation
- reordered conditions from cheap to expensive

[r27245]

[r27239]

[r27187]

[r27153]

[r27145]

Moved comments AFTER the ifs (where they belong to).

[r27117]

[r27107]

[r27101]