rt: Fix child-iteration bug in crate map.
std: add #[cfg(test)] reference to extra so we can benchmark libstd.
std: add preliminary str benchmark.
std: add #[bench] benchmarks for global and local heaps.
std: add #[bench] benchmarks for rand.
std: add #[bench] benchmarks for num::strconv
std: add benchmark for allocating-and-dropping a struct with a dtor.
std: various additional language benchmarks in util.
Add link_section attribute for static and fn items

This allows for control over the section placement of static, static
mut, and fn items.  One caveat is that if a static and a static mut are
placed in the same section, the static is declared first, and the static
mut is assigned to, the generated program crashes.  For example:

#[link_section=".boot"]
static foo : uint = 0xdeadbeef;

#[link_section=".boot"]
static mut bar : uint = 0xcafebabe;

Declaring bar first would mark .bootdata as writable, preventing the
crash when bar is written to.
Add a test for #5844 (a closed issue now)
test/run-fail: Un-xfail a test, make some other xfailed ones compile (they still don't work).
Add simple link_section test to exercise it
std: wrap "long" utf8 lines.
auto merge of #7958 : kemurphy/rust/link-section, r=alexcrichton

This allows for control over the section placement of static, static
mut, and fn items.  One caveat is that if a static and a static mut are
placed in the same section, the static is declared first, and the static
mut is assigned to, the generated program crashes.  For example:

#[link_section=".boot"]
static foo : uint = 0xdeadbeef;

#[link_section=".boot"]
static mut bar : uint = 0xcafebabe;

Declaring bar first would mark .bootdata as writable, preventing the
crash when bar is written to.
auto merge of #7980 : graydon/rust/misc-benchmarks, r=catamorphism

Some machinery for enabling #[bench] benchmarks in std and some examples showing how to write them.
auto merge of #7987 : alexcrichton/rust/tests-for-closed-issues, r=huonw

Closes #5844
auto merge of #7992 : huonw/rust/un-xfail, r=z0w0

...(they still don't work).
add a RandomAccessIterator trait
expand on double-ended iterators in the tutorial
document random-access iterators