Correct typo in the Iterator adapters section
guide-pointers.md: C sample code should match the Rust version.

Fix rust-lang/rust#17255
Fix typo in unsafe guide (s/xlibrary/library)
Correct tense
Add Option::{ok_or, ok_or_else}

These are the inverses of `Result::ok` and help to bridge `Option` and
`Result` based APIs.
auto merge of #17469 : sfackler/rust/into-result, r=aturon

This is the inverse of `Result::ok` and helps to bridge `Option` and
`Result` based APIs.
auto merge of #17512 : nodakai/rust/fix-ptr-guide, r=alexcrichton

Fix rust-lang/rust#17255

This is such a trivial change.  Devs: perhaps you might want to omit to run `make check` on Travis.
auto merge of #17515 : mbrubeck/rust/patch-1, r=alexcrichton

r? @steveklabnik
auto merge of #17511 : MatejLach/rust/iter_guide_typo, r=alexcrichton

The sentence "The new iterator `filter()` produces returns only the elements that that closure returned `true` for:"  can be structured as:

"The new iterator `filter()` produces only the elements that that closure returned `true` for:"

or as:

"The new iterator `filter()` returns only the elements that that closure returned `true` for:"

however, not both. 

I went with "produces", since it then talks about returning true and having "return" so close together doesn't sound nice. 
r @steveklabnik ?
Translate inline assembly errors back to source locations

Fixes #17552.