Implement Show for Bitv{,Set}

Closes #14531
Fix the handling of assignments to owning pointer paths in check_loans

Make check_for_assignment_to_restricted_or_frozen_location treat
mutation through an owning pointer the same way it treats mutation
through an &mut pointer, where mutability must be inherited from the
base path.

I also included GC pointers in this check, as that is what the
corresponding code in gather_loans/restrictions.rs does, but I don't
think there is a way to test this with the current language.

Fixes #14498.
auto merge of #14535 : sfackler/rust/bitv-show, r=alexcrichton

Closes #14531
rustc: Add lint for snake_case functions & methods.
libsyntax: Fix snake_case errors.

A number of functions/methods have been moved or renamed to align
better with rust standard conventions.

syntax::ext::mtwt::xorPush => xor_push
syntax::parse::parser::Parser => Parser::new

[breaking-change]
lib{std,core,debug,rustuv,collections,native,regex}: Fix snake_case errors.

A number of functions/methods have been moved or renamed to align
better with rust standard conventions.

std::reflect::MovePtrAdaptor => MovePtrAdaptor::new
debug::reflect::MovePtrAdaptor => MovePtrAdaptor::new
std::repr::ReprVisitor => ReprVisitor::new
debug::repr::ReprVisitor => ReprVisitor::new
rustuv::homing::HomingIO.go_to_IO_home => go_to_io_home

[breaking-change]
lib{serialize, uuid}: Fix snake case errors.

A number of functions/methods have been moved or renamed to align
better with rust standard conventions.

serialize::ebml::reader::Doc => seriaize::ebml::Doc::new
serialize::ebml::reader::Decoder => Decoder::new
serialize::ebml::writer::Encoder => Encoder::new

[breaking-change]
librustc: Fix snake case errors.

A number of functions/methods have been moved or renamed to align
better with rust standard conventions.

rustc::back::link::WriteOutputFile => write_output_file
rustc::middle::ty::EmptyBuiltinBounds => empty_builtin_bounds
rustc::middle::ty::AllBuiltinBounds => all_builtin_bounds
rustc::middle::liveness::IrMaps => IrMaps::new
rustc::middle::liveness::Liveness => Liveness::new
rustc::middle::resolve::NameBindings => NameBindings::new
rustc::middle::resolve::PrimitiveTypeTable => PrimitiveTypeTable::new
rustc::middle::resolve::Resolver => Resolver::new
rustc::middle::trans::datum::Datum => Datum::new
rustc::middle::trans::datum::DatumBlock => DatumBlock::new
rustc::middle::trans::datum::Rvalue => Rvalue::new
rustc::middle::typeck::infer::new_ValsAndBindings => ::infer::unify::ValsAndBindings::new
rustc::middle::typeck::infer::region_inference::RegionVarBindings => RegionVarBindings::new

[breaking-change]
windows: Allow snake_case errors for now.
auto merge of #14520 : Ryman/rust/SnakeCaseLint, r=alexcrichton

This enforces `snake_case` for functions and methods only. Might be worth extending it to fields and locals too at some point in the future.

A number of breaking changes each detailed in the attached commits.
auto merge of #14536 : zwarich/rust/issue-14498, r=luqmana

Make check_for_assignment_to_restricted_or_frozen_location treat
mutation through an owning pointer the same way it treats mutation
through an &mut pointer, where mutability must be inherited from the
base path.

I also included GC pointers in this check, as that is what the
corresponding code in gather_loans/restrictions.rs does, but I don't
think there is a way to test this with the current language.

Fixes #14498.
Register new snapshots
std: Recreate a `collections` module

As with the previous commit with `librand`, this commit shuffles around some
`collections` code. The new state of the world is similar to that of librand:

* The libcollections crate now only depends on libcore and liballoc.
* The standard library has a new module, `std::collections`. All functionality
  of libcollections is reexported through this module.

I would like to stress that this change is purely cosmetic. There are very few
alterations to these primitives.

There are a number of notable points about the new organization:

* std::{str, slice, string, vec} all moved to libcollections. There is no reason
  that these primitives shouldn't be necessarily usable in a freestanding
  context that has allocation. These are all reexported in their usual places in
  the standard library.

* The `hashmap`, and transitively the `lru_cache`, modules no longer reside in
  `libcollections`, but rather in libstd. The reason for this is because the
  `HashMap::new` contructor requires access to the OSRng for initially seeding
  the hash map. Beyond this requirement, there is no reason that the hashmap
  could not move to libcollections.

  I do, however, have a plan to move the hash map to the collections module. The
  `HashMap::new` function could be altered to require that the `H` hasher
  parameter ascribe to the `Default` trait, allowing the entire `hashmap` module
  to live in libcollections. The key idea would be that the default hasher would
  be different in libstd. Something along the lines of:

      // src/libstd/collections/mod.rs

      pub type HashMap<K, V, H = RandomizedSipHasher> =
            core_collections::HashMap<K, V, H>;

  This is not possible today because you cannot invoke static methods through
  type aliases. If we modified the compiler, however, to allow invocation of
  static methods through type aliases, then this type definition would
  essentially be switching the default hasher from `SipHasher` in libcollections
  to a libstd-defined `RandomizedSipHasher` type. This type's `Default`
  implementation would randomly seed the `SipHasher` instance, and otherwise
  perform the same as `SipHasher`.

  This future state doesn't seem incredibly far off, but until that time comes,
  the hashmap module will live in libstd to not compromise on functionality.

* In preparation for the hashmap moving to libcollections, the `hash` module has
  moved from libstd to libcollections. A previously snapshotted commit enables a
  distinct `Writer` trait to live in the `hash` module which `Hash`
  implementations are now parameterized over.

  Due to using a custom trait, the `SipHasher` implementation has lost its
  specialized methods for writing integers. These can be re-added
  backwards-compatibly in the future via default methods if necessary, but the
  FNV hashing should satisfy much of the need for speedier hashing.

A list of breaking changes:

* HashMap::{get, get_mut} no longer fails with the key formatted into the error
  message with `{:?}`, instead, a generic message is printed. With backtraces,
  it should still be not-too-hard to track down errors.

* The HashMap, HashSet, and LruCache types are now available through
  std::collections instead of the collections crate.

* Manual implementations of hash should be parameterized over `hash::Writer`
  instead of just `Writer`.

[breaking-change]
Fallout from the libcollections movement