rollup merge of #17888 : gmfawcett/patch-1

Author: alexcrichton

src/libcollections/bitv.rs

@@ -33,7 +33,7 @@
 //!     bv.set(0, false);
 //!     bv.set(1, false);
 //!
-//!     for i in range(2, max_prime) {
+//!     for i in iter::range_inclusive(2, (max_prime as f64).sqrt() as uint) {
 //!         // if i is a prime
 //!         if bv[i] {
 //!             // Mark all multiples of i as non-prime (any multiples below i * i