mozilla/rust — pull request #5524 by luqmana (2013-03-24 08:25:02+00:00)
Title: librustc: emit loop for expr_repeat instead of 2n instructions in [x, n]

`let v = [24, ..1000];` now more or less emits the same IR as:

```Rust
let mut i = 0;
while i < 1000 {
v[i] = 24;
i += 1;
}
```

LLVM will still turn it into a memset if possible with optimization on.