Update error message on compile
Single curly braces instead of double are being used
Add example of estimating pi using Monte Carlo simulation to std::rand
Add division by zero case to the `CheckedDiv` comment
Remove the dist function; it is more efficient to compare squared distances
rust.md: Explicitly point out how special `'static` is.

Drive-by: fix description of `&content` to point out that `&'f type`
is (as of today) only for type expressions.
Sort most attributes alphabetically
guide-runtime.md: remove redundant verb
guide-testing.md: add auxiliary verb
guide-unsafe.md: fix noun
Replace all references to "Win32" with "Windows".

For historical reasons, "Win32" has been used in Rust codebase to mean "Windows OS in general".
This is confusing, especially now, that Rust supports Win64 builds.

[breaking-change]
Replace #[cfg(target_os = "win32")] with #[cfg(target_os = "windows")]
Minor changes to `rust.md`, and `guide-ffi.md`.

  * `rust.md`: whanges for consistency

  * `guide-ffi.md`: wrapped inline code
Replace "ignore-win32" in tests with "ignore-windows"
~ -> Box in the manual

Fixes #16439
guide-unsafe.md: fix wording

Following a suggestion by Huon Wilson.
Guide: patterns.

Fixes #4417.
libnative: process spawning should not close inherited file descriptors

* The caller should be responsible for cleaning up file descriptors
* If a caller safely creates a file descriptor (via
  native::io::file::open) the returned structure (FileDesc) will try to
  clean up the file, failing in the process and writing error messages
  to the screen.
* This should not happen as the caller has no public interface for
  telling the FileDesc structure to NOT free the underlying fd.
* Alternatively, if another file is opened under the same fd held by
  the FileDesc structure returned by native::io::file::open, it will
  close the wrong file upon destruction.
libcore: rename private cmp macros

eq_impl! => partial_eq_impl!
totaleq_impl! => eq_impl!
ord_impl! => partial_ord_impl!
totalord_impl! => ord_impl!
auto merge of #16421 : ipetkov/rust/cmd-fd-fix-retry, r=alexcrichton

Retry pull requesting of https://github.com/rust-lang/rust/pull/16407 after accidentally messing up rebasing of branches and making bors think the PR was merged