It has been empty for nearly all systems. People who used to put stuff
in config.h can still create a config.h on their own and inject
-include (gcc) or /FI (msvc) into their CPPFLAGS.

Correct and simplify emitting Add/Sub on AMD64 now that should_be_same constraints are resolved with copies.

It is more consistent to use them and they are slightly faster to fetch.

Just state the copyright and the project the files belong to. You can
then find the COPYING file for the whole project.

beemit: Provide be_emit_node(), which merges the (almost) identical node emit functions of the backends.

Also use one common be_emit_nothing().

Remove now redundant (and sometimes wrong) location info from the panic messages.

Also factor out code that emits the label and comment at the beginning
of a basic block.

- We now always output dwarf3 so we can use DW_OP_call_frame_cfa and avoid
  construction location lists, but just reuse the callframe info lists.
- Backends have to emit debug info as callframe calculation changes:
  The ia32 backend has a preliminary implementation which assumes esp
  offset of frame_type_size at the beginning of a block (currently
  always true), the no-omit-fp mode assumes ebp relative addressing
  (which is correct except for the prolog/epilogue insns)

Remove the stabs debugoutput code and with it all the complexity of a
modular debug output system. The only remaining debug output module is
dwarf.

The opcode list was a member of irprog before which wasn't really
handled consistently. Also make sure opcodes are properly freed at
ir_finish().

This was an odd convention from the past, there's no need for it
anymore.

This tries to get the names in a consistent format. We basically have 2
views on register allocation/constraints now:

1) Register Requirements and Assigments are per-instruction. Each
   instruction has requirements on its inputs and outputs, register get
   assigned for outputs of an instruction (assignment is an attribute of
   an instruction, not of the Proj-nodes).
   The internal datastructures model this form!

   The functions here have the form:
     arch_get_irn_register_req_in(node, input_nr)
     arch_get_irn_register_in(node, input_nr)
     arch_get_irn_register_req_out(node, output_nr)
     arch_set_irn_register_out(node, output_nr, register)

2) Register Requirements and Assignments are on firm-values. This view
   allows to query/assign requirements and registers at the Proj nodes
   instead of the repsective predecessors.
   This is a convenience interface modeled on top of the other!

   The functions have the form:
     arch_get_irn_register_req(node)
     arch_get_irn_register(node)
     arch_set_irn_register(node, register)