+ 7.7.2000 Chris
+ Fixed some bugs in irgopt.c
+ Added some missing 'get_new_node' methods, so the new obstack contains
+ the correct nodes.
+
+ 6.7.2000 Chris
+ Renamed ir_vrfy to irn_vrfy and vrfy_graphg to irg_vrfy.
+ Solved some copy'n'paste problems. Deleted most debug-code!
+ Added comments to several files.
+
+ 6.7.2000 Goetz
+ Fixed bug in _r_ constructors for all four Div operations.
+ Fixed bug in turn_into_tuple: didn't remember the block.
+ Tested transform_node.
+