Moved integer trait and functions to submodule
Cleanup bigint
librustc: Implement overloading for the call operator behind a feature
gate.

This is part of unboxed closures.
Implement #[plugin_registrar]

See RFC 22.

[breaking-change]
Use phase(plugin) in bootstrap crates

Do this to avoid warnings on post-stage0 builds.
Use phase(plugin) in other crates
Use phase(plugin) in tests
Convert libraries to use #[plugin_registrar]
Convert tests to use #[plugin_registrar]
Add a test for deprecated phase(syntax)
Document rustc::plugin
Macro crates now depend on librustc
auto merge of #14554 : kmcallister/rust/plugin_registrar, r=cmr

This implements the design in rust-lang/rfcs#86.  It shouldn't be merged until that RFC is accepted, but it would be great if somebody has time to review the code before then.
auto merge of #14590 : pcwalton/rust/overloaded-call, r=nick29581

gate.

This is part of unboxed closures.

r? @nick29581
std: Remove the as_utf16_p functions

These functions are all much better expressed via RAII using the to_utf16()
method on strings. This refactoring also takes this opportunity to properly
handle when filenames aren't valid unicode when passed through to the windows
I/O layer by properly returning I/O errors.

All previous users of the `as_utf16_p` or `as_utf16_mut_p` functions will need
to convert their code to using `foo.to_utf16().append_one(0)` to get a
null-terminated utf16 string.

[breaking-change]
Moved integer trait and functions to submodule
Cleanup bigint
Add a --color flag to test binaries

It uses the same behavior as rustc's.
std: Move dynamic_lib from std::unstable to std

This leaves a deprecated reexport in place temporarily.

Closes #1457.
Add test for issue #13446

Closes #13446