fix warning
cfopt: remove loop/keepalive setting when moving Phis inside loops
cfopt: we remove unreachable code before begin, so no need to test for it
cfopt: remove exception where some critical edges were not produced

The were some comments in the code indicating that in case of SSA
destruction problems critical edges were not created. But we deal with
these cases anyway during SSA destruction so no need to avoid them
earlier.
cfopt: small cleanups
cfopt: rework control flow optimization

- No strange split between no-phi and phi variants anymore. The phi
  variant can perform everything now.
- Repeat till we reach the fixpoint.
lower_switch: cleanup, use C99
localopt: switch with just default proj can be replaced by Jmp
rework switch lowerer

- Normalize switch table now (sort + remove default entries)
- Correctly handle the case of multiple entries mapping to the same proj
  number.
cfopt: optimize switch functions

- For equal destinations merge the switch table entries and Proj nodes
- Handle Switches with just a default Proj like Jmp nodes
normalizing for 1 return increases Cond/Switch optimization chance
Fixed indentation.
Also dump condition code for ia32_SetccMem.
Do not create stc and cmc if only SF and ZF are needed.