You can still attach NoMem if no memory input is present.
This makes it more consistent with the Call node and fixes failing
get_ASM_mem in case of no memory input.

This makes it consistent with other functions like get_irn_arity().
(Though I must admit that we should change all these functions from
 "int" to unsigned at some point)

After the switch to C99, the foreach_ir_nodeset macro introduced a separate
loop variable, which shadowed the local variable "irn".  Thus, an uninitialized
pointer was passed to is_cfop.

This fixes backend/setmem.c.

Let list_for_each_entry(), list_for_each_entry_reverse() and list_for_each_entry_safe() declare their iterator variables.

It is identical to list_for_each(), though its comment claimed otherwise.

Let matrix_foreach(), matrix_foreach_in_col() and matrix_foreach_in_row() declare their iterator variables.

Remove now redundant (and sometimes wrong) location info from the panic messages.

Only define functions for which the user provided a renaming #define
(instead of forcing the users to create name for everything)
Only define iterator struct if a rename #define is present (instead of
forcing the user to define NO_ITERATOR if he doesn't want one)

also flip true/false in the implementation to match the documentation in
irnodeset.h

Add wrapper macros for pset_first() and pset_next(), which have the return type as additional parameter.