Fix long lines

Author: brson

src/test/run-pass/c-stack-returning-int64.rs

@@ -16,5 +16,6 @@ fn atoll(s: str) -> i64 {
 
 fn main() {
     assert atol("1024") * 10 == atol("10240");
-    assert (atoll("11111111111111111") * 10i64) == atoll("111111111111111110");
+    assert (atoll("11111111111111111") * 10i64)
+        == atoll("111111111111111110");
 }