Implement Lambdas

[Unknown6656]

maybe with the syntax

$my_func = Lambda($a, $b)
    return $a + $b
EndLambda

or:

$my_func = Lambda($a, $b) ->$a + $b

[Unknown6656]

relevant: https://stackoverflow.com/questions/63159208/emitting-marshalas-dynamically-using-reflection-emit