Compilation aborts when the member function of a mutable struct is called inside a higher-order function

[jonas-schmitt]

For the following code the compilation aborts without error message:

type real = f64;
type size_t = u64;

struct vector{
    n: size_t,
    buf: fn()->Buffer,
    set: fn(size_t, real) -> (),
    get: fn(size_t) -> real
}

fn get_vector(n: size_t)->vector{
    let tmp : Buffer = alloc_cpu(n as i32 * sizeof[real]());
    vector{
        n: n,
        buf: ||{tmp},
        set: |i,v|{bitcast[&mut[real]](tmp.data)(i) = v},
        get: |i| {bitcast[&[real]](tmp.data)(i)}
    }
}

fn loop(lower: size_t, upper: size_t, body: fn(size_t) -> ()) -> () {
    if lower < upper {
        body(lower);
        loop(lower+(1 as size_t), upper, body, return)
    }
}

fn main ()->(){
    let mut v = get_vector(10 as size_t);
    for i in loop (1 as size_t, 10 as size_t ) {
        v.set(i, 42.0);
    }
}

The problem only occurs if the variable "v" is declared mutable.
Impala flags: -emit-llvm -O3 -log-level error
impala commit 16c3ff7
thorin commit 72e23ec