Rationale: for what appear to be historical reasons only, the PatIdent contains
a Path rather than an Ident. This means that there are many places in the code
where an ident is artificially promoted to a path, and---much more problematically---
a bunch of elements from a path are simply thrown away, which seems like an invitation
to some really nasty bugs.
This commit replaces the Path in a PatIdent with a SpannedIdent, which just contains an ident
and a span.
This commit hooks rustdoc into the stability index infrastructure in two
ways:
1. It looks up stability levels via the index, rather than by manual
attributes.
2. It adds stability level information throughout rustdoc output, rather
than just at the top header. In particular, a stability color (with
mouseover text) appears next to essentially every item that appears
in rustdoc's HTML output.
Along the way, the stability index code has been lightly refactored.
floating point numbers for real.
This will break code that looks like:
let mut x = 0;
while ... {
x += 1;
}
println!("{}", x);
Change that code to:
let mut x = 0i;
while ... {
x += 1;
}
println!("{}", x);
Closes#15201.
[breaking-change]
Also change some code formatting.
lint::builtin becomes a sibling of lint::context in order to ensure that lints
implemented there use the same public API as lint plugins.
The immediate benefits are
* moving the state specific to a single lint out of Context, and
* replacing the soup of function calls in the Visitor impl with
more structured control flow
But this is also a step towards loadable lints.
