Turns out all six of these impls are incorrect.

This requires an updated LLVM with D31999 and D32000 to build libcore.

A basic hello world builds and runs successfully on the hexagon simulator.

Fixes rust-lang#33287

Fixes rust-lang#25164

…richton

Add bootstrap support for android

Haiku: fix initial platform support

Step::replace_one should put a one, not a zero (Issue rust-lang#41492)

Turns out all six of the replace_* impls were backwards.

Address platform-specific behavior in TcpStream::shutdown

Fixes rust-lang#25164

r? @rust-lang/libs from the GitHub thread, it seems like documenting this behavior is okay, but I want to make sure that's what you want.

…ion, r=jseyfried

Invalid module location

Fixes rust-lang#38110.

r? @jseyfried

…hton

Add Hexagon support

This requires an updated LLVM with https://reviews.llvm.org/D31999 and https://reviews.llvm.org/D32000 to build libcore.

A basic hello world builds and runs successfully on the hexagon simulator. libcore is fine with LLVM fixes, but libstd requires a lot more work since there's a custom rtos running on most hexagon cores. Running Linux sounds possible though, so maybe getting linux + musl going would be easier.

Here's the target file I've been using for testing
```
{
    "arch": "hexagon",
    "llvm-target": "hexagon-unknown-elf",
    "os": "none",
    "target-endian": "little",
    "target-pointer-width": "32",

    "data-layout": "e-m:e-p:32:32:32-a:0-n16:32-i64:64:64-i32:32:32-i16:16:16-i1:8:8-f32:32:32-f64:64:64-v32:32:32-v64:64:64-v512:512:512-v1024:1024:1024-v2048:2048:2048",
    "linker": "hexagon-clang",
    "linker-flavor": "gcc",
    "executables": true,
    "cpu": "hexagonv60"
}
```

…chton

Shrink the rust-src component

Before this change, the installable rust-src component had essentially the same contents as the rustc-src dist tarball, just additionally wrapped in a rust-installer.  As discussed on [internals], rust-src is only meant to support uses for the standard library, so it doesn't really need the rest of the compiler sources.

Now rust-src only contains libstd and its path dependencies, which roughly matches the set of crates that have rust-analysis data.  The result is **significantly** smaller, from 36MB to 1.3MB compressed, and from 247MB to 8.5MB uncompressed.

[internals]: https://internals.rust-lang.org/t/minimizing-the-rust-src-component/5117

Add a regression test for ICE rust-lang#33287

Fixes rust-lang#33287

…excrichton

Update num_cpus dependency to 1.x (1.4.0)