ir.CallStatement constructor fails if the arguments are not passed as keyword arguments

[wertysas]

What happened?

After the addition of a pre_init method to the CallStatment node class it is not possible to construct a CallStatement without passing a keyword argument.

What are the steps to reproduce the bug?

import loki.ir as ir
import loki.expression.symbols as sym

myfun = sym.ProcedureSymbol(name='myfun')
call = ir.CallStatement(myfun, (sym.IntLiteral(1),))   # this fails
# call = ir.CallStatement(name=myfun, arguments=(sym.IntLiteral(1),))   # this doesnt fail

Version

main branch

Platform (OS and architecture)

Mac OS

Relevant log output

File "callstmt_ctor_minimal_reproducible.py", line 5, in <module>
    call = ir.CallStatement(myfun, (sym.IntLiteral(1),))   # this fails
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/loki-venv/lib/python3.11/site-packages/pydantic/_internal/_dataclasses.py", line 141, in __init__
    s.__pydantic_validator__.validate_python(ArgsKwargs(args, kwargs), self_instance=s)
  File "loki/loki/ir/nodes.py", line 1005, in pre_init
    if 'arguments' in values.kwargs:
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: argument of type 'NoneType' is not iterable

Accompanying data

No response

Organisation

No response