Local mutual tail recursive optimization

[Jand42]

In translated code for local mutually tail-recursive functions, switch case is incorrectly falling over instead of terminating with a break and continuing the while loop.

Failing example:

let tailRecursionOptimizerBug() =
    let rec f x =
        if x = 0 then g x 1 else f (x - 1)
    and g x y =
        x + y
    f 5

Should return 1 but returns NaN.

[Jand42]

Another bug: arguments are not copied when in mutual tail-recursive calls a later argument needs the current value.

Failing example:

let mutualLetRecArgCopying() =
    let rec f x y z =
        if x = 0 then 
            if y = 0 then g z else y + z
        else f (x - 1) y z
    and g x = 
        f 0 1 x
    f 5 0 5

g loops to f with states 0, 1, 0 in translated code because the value of x is not copied before being overwritten.