Deduce the mode automatically from the given entity.

This removes the strange entity/type duality and we get rid of union symconst_symbol.

based on a patch by Luca Barbato <lu_zero@gentoo.org>

The file wasn't really meant to be included (it lacks the proper includes to be
useful on its own), the correct file to include is irnode.h.

Anyway the guards don't hurt either...

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 avoids the deprecated u''.

This is a major Makefile refactoring:
differentiate between:
- source files in $(srcdir)
- generated files in $(top_builddir)/gen
- object files in $(top_builddir)/$(variant)/ aka $(builddir)
- documentation in $(top_builddir)/doc

It is not usefull for optimization in most languages:
- In C/C++ you can't really change the value of enum constants as casting
  from/to integer has to produce the expected results.
- In Java (and other OO languages) enum members are objects so the
  libfirm enumeration type can't be used there anyway

This requires to actually compute volatility in a number of places.
Therefore, this also adds some helper functions to do that.

The new code has less options and variants, if you call irg_verify()
verification is performed, regardless of DEBUG_libfirm, or NDEBUG being
set and regardless of firm verification setting switches. On the other
side no atomic dump and abort is performed anymore, the call has to do
this, though an irg_assert_verify() function has been added as a
convenience measure.
There has also been a complete rewrite of the actual checking performed.
The new code is simpler, should produce more consistent output and
can report more than one error.

This reverts commit 3d1d2c43.

Creating a Bad node does not imply that it has users or is reachable
within an irg. While clearing the property is certainly correct as a
conservative approximation, it should not be necessary.

This node was used by OO code in the past, but newer versions of liboo
have their own node and don't need it anymore.

CopyB is normally used to transfer data on the stack or to enable compound
value calling conventions. Exceptions don't happen in these cases.

I don't really understand what it was supposed to do (because nodes
using/producing should be pretty much immovable anyway because of their
dependencies, so an additional pinning type appears unnecessary).
In practice there was no code differentiating between mem_pinned and exc_pinned.

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

They are considered low level operations now which just allocate/free a
block of memory on the stack. There is no highlevel typeinformation
attached anymore or support for heap allocation. Frontends/liboo should
provide their custom highlevel nodes if they need these features.

the templates are now friendlier for usage outside of libfirm

Templates are put in separate files now, making the main script more
generic in nature

They weren't used in a sensible way and their semantic for
non-arithmetic ops was unclear.
Also implicitely fixes a bunch of bugs where these where set but no op_index
was set at the same time.

oparity_unary, oparity_binary require opindex to be set, which wasn't
always the case.
Also people seem to expect certain semantics from unops/binops, like
being arithmetic operations. So we shouldn't automatically set
oparity_XXX.