This removes one exception in the tidy lint 'pal'.

This removes exceptions in the tidy lint 'pal'.

Also remove exceptions in tidy lint 'pal'.

Fix rust-lang#36648

 * `is_ascii_alphabetic`
 * `is_ascii_uppercase`
 * `is_ascii_lowercase`
 * `is_ascii_alphanumeric`
 * `is_ascii_digit`
 * `is_ascii_hexdigit`
 * `is_ascii_punctuation`
 * `is_ascii_graphic`
 * `is_ascii_whitespace`
 * `is_ascii_control`

This addresses issue rust-lang#39658.

This commit adds three new builders, one OSX, one Linux, and one MSVC, which
will produce "nightlies" with LLVM assertions disabled. Currently all nightly
releases have LLVM assertions enabled to catch bugs before they reach the
beta/stable channels. The beta/stable channels, however, do not have LLVM
assertions enabled.

Unfortunately though projects like Servo are stuck on nightlies for the near
future at least and are also suffering very long compile times. The purpose of
this commit is to provide artifacts to these projects which are not distributed
through normal channels (e.g. rustup) but are provided for developers to use
locally if need be.

Logistically these builds will all be uploaded to `rustc-builds-alt` instead of
the `rustc-builds` folder of the `rust-lang-ci` bucket. These builds will stay
there forever (until cleaned out if necessary) and there are no plans to
integrate this with rustup and/or the official release process.

Unfortunately it appears to spuriously fail so we can't gate on it

The length of a URL is usually not under our control, and Markdown
provides no way to split a URL in the middle.  Therefore, comment
lines consisting _solely_ of a URL (possibly with a Markdown link
label in front) should be exempt from the line-length restriction.

Inline hyperlink destinations ( `[foo](http://...)` notation ) are
_not_ exempt, because it is my arrogant opinion that long lines of
that type make the source text illegible.

The patch adds dependencies on the `regex` and `lazy_static` crates
to the tidy utility.  This _appears_ to Just Work, but if you would
rather not have that dependency I am willing to provide a hand-written
parser instead.

Refactor stdlib for pal

This is a small step towards [pal](https://internals.rust-lang.org/t/refactoring-std-for-ultimate-portability/4301/40). I moved all platform-specific code from `libstd/{path,f32,f64}.rs` to `libstd/sys`.
For the float implementation, I moved only the parts that are currently platform-specific, which leaves direct dependency on libc in `libstd/f32.rs` and `libstd/f64.rs`. I don't know if it is better to move all the dependency to libc in  `sys`.

Dont segfault if btree range is not in order

This is a first attempt to fix issue rust-lang#33197.  The issue is that the BTree iterator uses next_unchecked for fast iteration, but it can be tricked into running off the end of the tree and segfaulting if range is called with a maximum that is less than the minimum.

Since a user defined Ord should not determine the safety of BTreeMap, and we still want fast iteration, I've implemented the idea of @gereeter and walk the tree simultaneously searching for both keys to make sure that if our keys diverge, the min key is to the left of our max key.  I currently panic if that is not the case.

Open questions:

1.  Do we want to panic in this error case or do we want to return an empty iterator?  The drain API panics if the range is bad, but drain is given a range of index values, while this is a generic key type.  Panicking is brittle and returning an empty iterator is probably the most flexible and matches what people would want it to do... but artificially returning a BTreeMap::Range with start==end seems like a pretty weird and unnatural thing to do, although it's doable since those fields are not accessible.

The same question for other weird cases:
2.  (Included(101), Excluded(100)) on a map that contains [1,2,3].  Both BTree edges end up on the same part of the map, but comparing the keys shows the range is backwards.
3.  (Excluded(5), Excluded(5)).  The keys are equal but BTree edges end up backwards if the map contains 5.
4.  (Included(5), Excluded(5)).  Should naturally produce an empty iterator, right?

std: Add retain method for HashMap and HashSet

Fix rust-lang#36648

r? @bluss

Add equivalents of C's <ctype.h> functions to AsciiExt.

 * `is_ascii_alphabetic`
 * `is_ascii_uppercase`
 * `is_ascii_lowercase`
 * `is_ascii_alphanumeric`
 * `is_ascii_digit`
 * `is_ascii_hexdigit`
 * `is_ascii_punctuation`
 * `is_ascii_graphic`
 * `is_ascii_whitespace`
 * `is_ascii_control`

This addresses issue rust-lang#39658.

Lightly tested on x86-64-linux.  tidy complains about the URLs in the documentation making lines too long, I don't know what to do about that.

macros: fix ICE on certain sequence repetitions

Fixes rust-lang#39709.
r? @nrc

travis: Add builders without assertions

This commit adds three new builders, one OSX, one Linux, and one MSVC, which
will produce "nightlies" with LLVM assertions disabled. Currently all nightly
releases have LLVM assertions enabled to catch bugs before they reach the
beta/stable channels. The beta/stable channels, however, do not have LLVM
assertions enabled.

Unfortunately though projects like Servo are stuck on nightlies for the near
future at least and are also suffering very long compile times. The purpose of
this commit is to provide artifacts to these projects which are not distributed
through normal channels (e.g. rustup) but are provided for developers to use
locally if need be.

Logistically these builds will all be uploaded to `rustc-builds-alt` instead of
the `rustc-builds` folder of the `rust-lang-ci` bucket. These builds will stay
there forever (until cleaned out if necessary) and there are no plans to
integrate this with rustup and/or the official release process.

…=japaric

test: Remove sanitizer-thread test

Unfortunately it appears to spuriously fail so we can't gate on it

…, r=alexcrichton

Add filename when running rustdoc --test on a markdown file

r? @alexcrichton

…lexcrichton

tidy: exempt URLs from the line length restriction

The length of a URL is usually not under our control, and Markdown
provides no way to split a URL in the middle.  Therefore, comment
lines consisting _solely_ of a URL (possibly with a Markdown link
label in front) should be exempt from the line-length restriction.

Inline hyperlink destinations ( `[foo](http://...)` notation ) are
_not_ exempt, because it is my arrogant opinion that long lines of
that type make the source text illegible.

The patch adds dependencies on the `regex` and `lazy_static` crates
to the tidy utility.  This _appears_ to Just Work, but if you would
rather not have that dependency I am willing to provide a hand-written
parser instead.