As we continue to add more crates to the compiler and use them to implement
various features we want to be sure we're not accidentally expanding the API
surface area of the compiler! To that end this commit adds a new `run-make` test
which will attempt to `extern crate foo` all crates in the sysroot, verifying
that they're all unstable.

This commit discovered that the `std_shim` and `test_shim` crates were
accidentally stable and fixes the situation by deleting those shims. The shims
are no longer necessary due to changes in Cargo that have happened since they
were originally incepted.

In the long run we want to separate out the dist builders from the test
builders. This provides us leeway to expand the dist builders with more tools
(e.g. Cargo and the RLS) without impacting cycle times.

Currently the Travis dist builders double-up the platforms they provide builds
for, so I figured we could try that out for MSVC as well. This commit adds a new
AppVeyor builder which runs a dist for all the MSVC targets:

* x86_64-pc-windows-msvc
* i686-pc-windows-msvc
* i586-pc-windows-msvc

If this takes too long and/or times out we'll need to split this up. In any case
we're going to need more capacity from AppVeyor no matter what becaue the two
pc-windows-gnu targets can't cross compile so we need at least 2 more builders
no matter what.

Previously InlineAsm was an Rvalue, but its semantics doesn’t really match the semantics of an
Rvalue – rather it behaves more like a Statement.

Fixes rust-lang#39868

This commit changes all MSVC rustc binaries to be compiled with
`-C target-feature=+crt-static` to link statically against the MSVCRT instead of
dynamically (as it does today). This also necessitates compiling LLVM in a
different fashion, ensuring it's compiled with `/MT` instead of `/MD`.

cc rust-lang#37406

Re: 48b3dd1

Add a test that -fPIC is applied

r? @alexcrichton Can it really be this simple? I've tested it works, but still testing that it used to fail.

rustc: Link statically to the MSVCRT

This commit changes all MSVC rustc binaries to be compiled with
`-C target-feature=+crt-static` to link statically against the MSVCRT instead of
dynamically (as it does today). This also necessitates compiling LLVM in a
different fashion, ensuring it's compiled with `/MT` instead of `/MD`.

cc rust-lang#37406

test: Verify all sysroot crates are unstable

As we continue to add more crates to the compiler and use them to implement
various features we want to be sure we're not accidentally expanding the API
surface area of the compiler! To that end this commit adds a new `run-make` test
which will attempt to `extern crate foo` all crates in the sysroot, verifying
that they're all unstable.

This commit discovered that the `std_shim` and `test_shim` crates were
accidentally stable and fixes the situation by deleting those shims. The shims
are no longer necessary due to changes in Cargo that have happened since they
were originally incepted.

…, r=brson

appveyor: Move MSVC dist builds to their own builder

In the long run we want to separate out the dist builders from the test
builders. This provides us leeway to expand the dist builders with more tools
(e.g. Cargo and the RLS) without impacting cycle times.

Currently the Travis dist builders double-up the platforms they provide builds
for, so I figured we could try that out for MSVC as well. This commit adds a new
AppVeyor builder which runs a dist for all the MSVC targets:

* x86_64-pc-windows-msvc
* i686-pc-windows-msvc
* i586-pc-windows-msvc

If this takes too long and/or times out we'll need to split this up. In any case
we're going to need more capacity from AppVeyor no matter what becaue the two
pc-windows-gnu targets can't cross compile so we need at least 2 more builders
no matter what.

[MIR] Make InlineAsm a Statement

Previously InlineAsm was an Rvalue, but its semantics doesn’t really match the semantics of an
Rvalue – rather it behaves more like a Statement.

r? @nikomatsakis you wanted this to happen

…richton

libstd needs update for pending libc change

This  updates libstd to accommodate the fixes made in rust-lang/libc#523

Fixes rust-lang#39868

Fixes overflow in libsdt/io/cursor.rs "seek"

Fixes rust-lang#39631
Test which fails (with old implementation), then fix to implementation.

Remove noop method `Substs::params()`

Re: 48b3dd1 & 7a8d482