At leat that's what qemu and arm-linux-gnueabi assume by default
TODO: add a commandline switch for endianess

- We now create a spill/reload/phi-web and take the largest necessary
  reload size to determine the size of the entities and the spills.
- Some cleanups

This also disables the memcombine optimisation if unaligned stores are
not supported by the backend.
We may add some tests in the future to reenable this in cases where we
can prove that the combined store is aligned.

This allows the fronted to register a dump+verify callback for the
lowering transformations performed by the backends.

All users of NEW_ARR_A used it to construct a simple array, yet noone
cared about it actually being an array with a length field in front. For
this simple use case you should use ALLOCAN.

This mainly adds comments explaining the situation and avoids an extra
graph walk.

This works around a problem with modeling control flow for calls to
setjmp and similar functions.

- The backends can simply perform the finish_graph() steps in the emit()
  phase.

- You can now construct the lookup table separately and perform the
  lowering selectively on irgs (instead of the whole program at once)
  while reusing the lookup table.
- Simplified API a bit.
- Remove i_mapper_RuntimeCall. All users are simpler by doing the
  transformations directly instead of filling in runtime_rt
  structures...

before_abi() callback was removed, you can simply put that code at the end
of the init() callback. custom_abi flag was removed, if a backend needs the
be_abi_introduce() stuff (formerly custom_abi == false) then it can call
it at the end of the init() callback.

The code was only working on ia32 and contains several ia32 specific
bits, so keep it in the ia32 backend for now. At least the amd64 backend
will require a different implementation of PIC.

The backends which support rotl now match for or(shl,shr) patterns.

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.