Apply lint attrs to individual "use" declarations

Fixes #10534
Remove special rooting code from trans

[breaking-change]

cc #11586
rustc: remove usage of root_map from astencode
rustc: Remove root_map usage from _match
rustc: Remove root_map usage from lifetime
rustc: Remove root_map entirely
Update tests and move other tests around
rustc: Remove obsolete error_out_of_root_scope variant
Treat @T like ~T in borrowck

`@` pointers used to have special rooting and regions management. With `@`
moving to standalone library, we don't need to keep that special
treatment around. This patch modifies the way `@` pointers are treated by
treating them as if they were `~` pointers

Region checker and borrow checker were modified in this patch.

Closes #11586

[breaking-change]
rustc: Remove moved_variables_set
syntax: fix de-@rooting fallout
rustc: fix de-@rooting fallout
fix std::f32 and std::f64 constants

Some of the constant values in std::f32 were incorrectly copied from
std::f64.  More broadly, both modules defined their constants redundantly
in two places, which is what led to the bug.  Moreover, the specs for
some of the constants were incorrent, even when the values were correct.

Closes #13297.  Closes #11537.
Register new snapshots

These are the first successful snapshots after the LLVM upgrade, built with LLVM
that requires C++11
Calibrate span for method call error messages

Specifically, the method parameter cardinality mismatch or missing
method error message span now gets method itself exactly. It was the
whole expression.

Closes #9390
Closes #13684
Closes #13709
Prevent unsized types being stored in variables

Closes #13376.
rustdoc: fix de-@rooting fallout
auto merge of #13710 : aturon/rust/float-constants, r=brson

Some of the constant values in std::f32 were incorrectly copied from
std::f64.  More broadly, both modules defined their constants redundantly
in two places, which is what led to the bug.  Moreover, the specs for
some of the constants were incorrect, even when the values were correct.

Closes #13297.  Closes #11537.
auto merge of #13559 : FlaPer87/rust/remove-special-root, r=nikomatsakis

This patch removes the special auto-rooting for `@` from the borrow checker. With `@` moving into a library, it doesn't make sense to keep this code around anymore. It also simplifies `trans` by removing root checking from there 

@nikomatsakis

Closes: #11586
Fix Vim indent regressions from #13600.

The change in #13600 was incorrect, containing a bad regular expression;
inside an indent function, errors are silently ignored (and the ``~=``
operation will return 0), so it just always failed, causing the cases
that were supposed to be caught to not be caught and making things like
the ``match`` example shown above or struct field definitions regress.

I have fixed the regular expression to what it should have been. This is
still imperfect, of course, not handling cases like where the first
argument to a function is a function call (``foo(bar(),``), but it'll do
for now.