Constrain maximum lifetime of stack closures that capture variables to be limited by the innermost repeating scope.

Fixes #7336.

r? whomever.

This patch updates the existing manpage and creates new pages for all of the rust command line tools. Closes #7484.

Just getting my feet wet.

This is much faster for strings, and eventually when there is a
buffered reader of some sort, will be much faster for files.

Reading example.json 100 times before was around 1.18s.
After:
- reading from string 0.68s
- reading from file 1.08s (extra time is all in io::Reader)

Also:
- fixes #7611 - error when parsing strings and we hit EOF
- updates definition of whitespace in json should only be the 4 ascii whitespace chars

All of the examples were still using `core::` instead of `std::` and  needed a `use std::rand;` at the top to compile
Most of the examples had
    `rng = rand::rng();`
instead of
    `let mut rng = rand::rng();`

I don't think we have this yet. This makes `&mut [T]` much more flexible.

r? @strcat (or whomever)

I added documentation for when to use and not to use `c_void`, since it tripped me up when I started. (See issue #7627)

This is much faster for strings, and eventually when there is a
buffered reader of some sort.

Reading example.json 100 times before was around 1.18s.
After:
- reading from string 0.68s
- reading from file 1.08s (extra time is all in io::Reader)

Closes #7625

Fixes #2951

Added Add and Sub traits for pointer arithmetic. Any type that is a ```std::num::Int``` can be added to or subtracted from a pointer. Also my additions did not require any unsafe code, and the operators themselves are safe. Fixes #2122.

The examples were still using `core::` instead of `std::`
All of the examples needed a `use std::rand;` at the top to compile
Most of the examples had
    `rng = rand::rng();`
instead of
    `let mut rng = rand::rng();`

Implemented ptr arithmetic for *T and *mut T. Tests passing

auto merge of #7637 : pnkfelix/rust/fsk-guard-against-stale-libraries-issue3225-safeguarded, r=graydon

When building Rust libraries (e.g. librustc, libstd, etc), checks for
and verbosely removes previous build products before invoking rustc.
(Also, when Make variable VERBOSE is defined, it will list all of the
libraries matching the object library's glob after the rustc
invocation has completed.)

When installing Rust libraries, checks for previous libraries in
target install directory, but does not remove them.

The thinking behind these two different modes of operation is that the
installation target, unlike the build tree, is not under the control
of this infrastructure and it is not up to this Makefile to decide if
the previous libraries should be removed.

Fixes #3225 (at least in terms of mitigating the multiple library
problem by proactively warning the user about it.)

vec::with_capacity: do one alloc for non-managed + ptr module improvements

Closes #7625

r? @graydon, @nikomatsakis, @pcwalton, or @catamorphism

Sorry this is so huge, but it's been accumulating for about a month. There's lots of stuff here, mostly oriented toward enabling multithreaded scheduling and improving compatibility between the old and new runtimes. Adds task pinning so that we can create the 'platform thread' in servo.

[Here](https://github.com/brson/rust/blob/e1555f9b5628af2b6c6ed344cad621399cb7684d/src/libstd/rt/mod.rs#L201) is the current runtime setup code.

About half of this has already been reviewed.

d3be8ab r=brson
05eb3cf r=thestinger
c80f4e1 r=huonw
8c27af1 r=huonw
0eee0b6 r=cmr
ea2756a r=thestinger

it's a test to make sure a feature is *not* implemented, but it is now
implemented

`malloc` already returns memory correctly aligned for every possible
type in standard C, and that's enough for all types in Rust too

The free-standing functions in f32, f64, i8, i16, i32, i64, u8, u16,
u32, u64, float, int, and uint are replaced with generic functions in
num instead.

This means that instead of having to know everywhere what the type is, like

~~~
f64::sin(x)
~~~

You can simply write code that uses the type-generic versions in num instead, this works for all types that implement the corresponding trait in num.

~~~
num::sin(x)
~~~

Note 1: If you were previously using any of those functions, just replace them
with the corresponding function with the same name in num.

Note 2: If you were using a function that corresponds to an operator, use the
operator instead.

Note 3: This is just https://github.com/mozilla/rust/pull/7090 reopened against master.