Copy it before x87_kill_deads() instead of after it, so x87_kill_deads() does not need to conditionally copy it.

Just flush the fp stack, only check for the correct number of fp values in debug builds.

Now more than one node can be pushed through a Perm.
After pushing the first node through a Perm, we next inspected the Perm itself (the new schedule predecessor of the moved node), which obviously cannot be pushed through itself.

Do not leave out the last (highest numbered) irg.

some inputs had "no requirement" set instead of the correct one

irverify already checks the dominance property

(It was set to NULL in the past to support the STA-architecture, but
 that backend is not maintained anymore)

They were used to selectively disable parts of the algorithm for
measurements in the paper. We now know that we always want them switched
on so remove the switches to simplify the code.

Because otherwise we confuse users with free_ir_graph vs.
remove_irp_irg. Change it so that free_ir_graph also removes the graph
from the irp list.

Make function definitions prototype declarations.