This reverts commit 19cccd2b.

The situation can actually occur:
The spiller might reload an operand of a CopyKeep right before the CopyKeep.
This defeats the entire purpose of the CopyKeep, so the no-spill Copy right before the CopyKept node is necessary.

Newer Linux systems compile ar with --enable-deterministic-archives,
which conflicts with the u modifier.

Now only e.g. 'setmask' works, but 'SetMAsK' does not anymore.
I think, the loss is acceptable.

This is handled earlier and there are no memory clobbers anymore in gen_ASM().

In particular remove the unnecessary 'sparc_is_valid_clobber()'.
The wrapper 'be_is_valid_clobber()' already handles 'memory' and 'cc'.

The algorithm now also works for Calls with exception Projs.

The simple tp_opcode enum is enough, no need to have dispatch tables and
information structs behind each type kind.

There is no need for dispatch through tpop, they all use the same
underlying data structure anyway, so just work on that in
get_compound_xxx()

Except for two users, all users add 1 immediately anyway.
Of the two exceptions one of them (in kill_unused_stacknodes()) is wrong, so this is now corrected.
The other one is exchange(), which now just uses ->in, which is fine, since it handles node interna anyway.