In case of endless loops, there is no user of Start, so the missing keeps walker keeps Start's results.
Then the be_keep_if_unused() workaround does not trigger, because after rewiring the initial SP's users (here the Keep) to the IncSP it has one user.
But the IncSP is placed after the Keep in the schedule.
This either makes the verifier unhappy (arm) or gets erroneously removed by the dead nodes walker (sparc).
This solution is not entierly correct, but is consistent with what the ia32 backend does.
The correct solution would be a memory output for IncSP.

Checking the register implicitly covers checking for a data mode.

Add callbacks on functions that really need them instead.

* No \n at end; panic() adds one
* No punctuation mark at end
* Lowercase first letter

* It was retrieved from the arch_env before.
* Also rename be_abi_fix_stack_nodes() to be_fix_stack_nodes().

All other structs holding a register class call it cls, too.

- 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 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.

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.

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

The only user knwos, where its sp is.