Too big functions crash the system

[uuk0]

Functions requiring EXTENDED_ARG instructions somehow crash our system with a recursion exception

Tested with more than 256 local variable names

[uuk0]

TestCase:

import string

code = "def target():\n"

for string in itertools.product(string.ascii_lowercase, repeat=2):
    code += f"    _{''.join(string)} = 0\n"

code += "    return _zz"

space = {}
exec(code, space)

target = space["target"]
self.assertEqual(target(), 0)

mutable = MutableFunction(target)
mutable.reassign_to_function()

self.assertEqual(target(), 0)

[uuk0]

Seems like we need to rewrite optimise_tree() to be non-recursive