This crate moves the compiler's error reporting to using the `termcolor` crate
from crates.io. Previously rustc used a super-old version of the `term` crate
in-tree which is basically unmaintained at this point, but Cargo has been using
`termcolor` for some time now and tools like `rg` are using `termcolor` as well,
so it seems like a good strategy to take!

Note that the `term` crate remains in-tree for libtest. Changing libtest will be
a bit tricky due to how the build works, but we can always tackle that later.

cc rust-lang#45728

move test issue-32950 to run-pass

cc rust-lang#38356

Suggest type for overflowing bin/hex-literals

Fixes rust-lang#48073

For hexadecimal and binary literals, which overflow, it gives an additional note to the warning message, like in this [comment](rust-lang#48073 (comment)).

Additionally it will suggest a type (`X < Y`):
- `iX`: if literal fits in `uX` => `uX`, else => `iY`
- `-iX` => `iY`
- `uX` => `uY`

Exceptions: `isize`, `usize`. I don't think you can make a good suggestion here. The programmer has to figure it out on it's own in this case.

r? @oli-obk

…henkov

Expand items before their derives

continuation of rust-lang#41029

At this point all I've done is naively rebased on top of `master` and fixed the code enough to compile. I'm not even sure if it works because my local build stopped here:

```
C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\VC\VCTargets\Microsoft.CppBuild.targets(317,5): error MSB3491: Could not write lines to file "emscripten
-optimizer.dir\Release\emscript.63209ED8.tlog\emscripten-optimizer.lastbuildstate". The specified path, file name, or both are too long. The fully qualified file name must be less
than 260 characters, and the directory name must be less than 248 characters. [C:\Users\cyber\Rust\rust\build\x86_64-pc-windows-msvc\stage0-rustc\x86_64-pc-windows-msvc\release\bui
ld\rustc_binaryen-aaf5e3b308543526\out\build\src\emscripten-optimizer\emscripten-optimizer.vcxproj]
```

So I'm going to be relying on Travis to run tests unless I can fix this error.

rustc: Migrate to `termcolor` crate from `term`

This crate moves the compiler's error reporting to using the `termcolor` crate
from crates.io. Previously rustc used a super-old version of the `term` crate
in-tree which is basically unmaintained at this point, but Cargo has been using
`termcolor` for some time now and tools like `rg` are using `termcolor` as well,
so it seems like a good strategy to take!

Note that the `term` crate remains in-tree for libtest. Changing libtest will be
a bit tricky due to how the build works, but we can always tackle that later.

cc rust-lang#45728

Fixed rust-lang#48425 : Various functions taking a `TyCtxt` and a `Span` should be taking a `TyCtxtAt`

Hi @oli-obk
I have done some code refactoring to fix rust-lang#48425, Please let me know if anything else is required on this.

Optimize str::repeat

Improves the performance of `str::repeat` by bulk copying. Here is the benchmarks of `"abcde".repeat(n)`:

|`n`|old [ns/iter]|new [ns/iter]|diff [%]|
---|---|---|---
|1|27.205|27.421|+0.794|
|2|27.500|27.516|+0.0581|
|3|27.923|27.648|-0.985|
|4|31.206|30.145|-3.40|
|5|35.144|31.861|-9.34|
|7|43.131|34.621|-19.7|
|10|54.945|36.203|-34.1|
|100|428.31|52.895|-87.7|

…h, r=rkruppe

Refactor contrived match.

…hton

Remove useless powerpc64 entry from ARCH_TABLE

Hope, I understood the scope of the fix correctly. closes rust-lang#47737