bechordal: Simplify get_next_free_reg() by priming the set of available registers only with the allocatable registers.

The only user of this information (bechordal) can just check the register requirement type.

beirgmod: Do not set registers for the Perm results in insert_Perm_before() just to clear them afterwards.

This was missed when changing insert_Perm_after() to insert_Perm_before().

The only user of this information (bechordal) can just check, whether a register is assigned.

arch_register_type_virtual is sufficient.

They must match, even for joker registers.

bearch: Assert, instead of test, that the register requirement is not arch_register_req_type_none in arch_reg_is_allocatable().

If it is, something is very wrong.

Projs are not scheduled, so they will fail this test later on.

belive: Assert that only scheduled nodes are used in _value_dominates_intrablock() and _value_strictly_dominates_intrablock().

bearch: Remove special handling that a node has no backend info, when getting a register requirement of the node.

This should not occur anymore.

This is relevant, when there is an allocateable register with a higher number than some non-allocateable register.

ir: Shuffle node macros, so functions in the header declaring the macros use the inline versions of the node functions.