Auto merge of #32968 - alexcrichton:update-suport, r=brson

doc: Update our tier support

This modifies our listing of tiered platforms a few ways:

* All lists are alphabetized based on target now
* Lots of targets are moved up to "Tier 2" as we're gating on all these builds
  and official releases are provided (and installable via rustup).
* A few targets now list having a compiler + cargo now as well.

No more platforms have been moved up to Tier 1 at this time, however. The only
real candidate is ``x86_64-unknown-linux-musl`, but that's not *quite* to a tier
1 level of quality just yet so let's hold off for another release or so to iron
it out a bit.

diff --combined src/doc/book/getting-started.md
index 1fe3f6da0ebc74c82f6bdca3acf70fba243f5056,3a6b014d7c7f9ba7af7281f34e57c89f79f4921e..3a20663cda62ac6a900a249d15bc4d6bb3029c7e
--- 1/src/doc/book/getting-started.md
--- 2/src/doc/book/getting-started.md
+++ b/src/doc/book/getting-started.md
@@@ -39,13 -39,13 +39,13 @@@ Specifically they will each satisfy th
  
  |  Target                       | std |rustc|cargo| notes                      |
  |-------------------------------|-----|-----|-----|----------------------------|
- | `i686-pc-windows-msvc`        |  ✓  |  ✓  |  ✓  | 32-bit MSVC (Windows 7+)   |
- | `x86_64-pc-windows-msvc`      |  ✓  |  ✓  |  ✓  | 64-bit MSVC (Windows 7+)   |
- | `i686-pc-windows-gnu`         |  ✓  |  ✓  |  ✓  | 32-bit MinGW (Windows 7+)  |
- | `x86_64-pc-windows-gnu`       |  ✓  |  ✓  |  ✓  | 64-bit MinGW (Windows 7+)  |
  | `i686-apple-darwin`           |  ✓  |  ✓  |  ✓  | 32-bit OSX (10.7+, Lion+)  |
- | `x86_64-apple-darwin`         |  ✓  |  ✓  |  ✓  | 64-bit OSX (10.7+, Lion+)  |
+ | `i686-pc-windows-gnu`         |  ✓  |  ✓  |  ✓  | 32-bit MinGW (Windows 7+)  |
+ | `i686-pc-windows-msvc`        |  ✓  |  ✓  |  ✓  | 32-bit MSVC (Windows 7+)   |
  | `i686-unknown-linux-gnu`      |  ✓  |  ✓  |  ✓  | 32-bit Linux (2.6.18+)     |
+ | `x86_64-apple-darwin`         |  ✓  |  ✓  |  ✓  | 64-bit OSX (10.7+, Lion+)  |
+ | `x86_64-pc-windows-gnu`       |  ✓  |  ✓  |  ✓  | 64-bit MinGW (Windows 7+)  |
+ | `x86_64-pc-windows-msvc`      |  ✓  |  ✓  |  ✓  | 64-bit MSVC (Windows 7+)   |
  | `x86_64-unknown-linux-gnu`    |  ✓  |  ✓  |  ✓  | 64-bit Linux (2.6.18+)     |
  
  ### Tier 2
@@@ -63,13 -63,28 +63,28 @@@ these platforms are required to have ea
  
  |  Target                       | std |rustc|cargo| notes                      |
  |-------------------------------|-----|-----|-----|----------------------------|
- | `x86_64-unknown-linux-musl`   |  ✓  |     |     | 64-bit Linux with MUSL     |
+ | `aarch64-apple-ios`           |  ✓  |     |     | ARM64 iOS                  |
+ | `aarch64-unknown-linux-gnu`   |  ✓  |  ✓  |  ✓  | ARM64 Linux (2.6.18+)      |
  | `arm-linux-androideabi`       |  ✓  |     |     | ARM Android                |
- | `arm-unknown-linux-gnueabi`   |  ✓  |  ✓  |     | ARM Linux (2.6.18+)        |
- | `arm-unknown-linux-gnueabihf` |  ✓  |  ✓  |     | ARM Linux (2.6.18+)        |
- | `aarch64-unknown-linux-gnu`   |  ✓  |     |     | ARM64 Linux (2.6.18+)      |
+ | `arm-unknown-linux-gnueabi`   |  ✓  |  ✓  |  ✓  | ARM Linux (2.6.18+)        |
+ | `arm-unknown-linux-gnueabihf` |  ✓  |  ✓  |  ✓  | ARM Linux (2.6.18+)        |
+ | `armv7-apple-ios`             |  ✓  |     |     | ARM iOS                    |
+ |`armv7-unknown-linux-gnueabihf`|  ✓  |  ✓  |  ✓  | ARMv7 Linux (2.6.18+)      |
+ | `armv7s-apple-ios`            |  ✓  |     |     | ARM iOS                    |
+ | `i386-apple-ios`              |  ✓  |     |     | 32-bit x86 iOS             |
+ | `i586-pc-windows-msvc`        |  ✓  |     |     | 32-bit Windows w/o SSE     |
  | `mips-unknown-linux-gnu`      |  ✓  |     |     | MIPS Linux (2.6.18+)       |
+ | `mips-unknown-linux-musl`     |  ✓  |     |     | MIPS Linux with MUSL       |
  | `mipsel-unknown-linux-gnu`    |  ✓  |     |     | MIPS (LE) Linux (2.6.18+)  |
+ | `mipsel-unknown-linux-musl`   |  ✓  |     |     | MIPS (LE) Linux with MUSL  |
+ | `powerpc-unknown-linux-gnu`   |  ✓  |     |     | PowerPC Linux (2.6.18+)    |
+ | `powerpc64-unknown-linux-gnu` |  ✓  |     |     | PPC64 Linux (2.6.18+)      |
+ |`powerpc64le-unknown-linux-gnu`|  ✓  |     |     | PPC64LE Linux (2.6.18+)    |
+ | `x86_64-apple-ios`            |  ✓  |     |     | 64-bit x86 iOS             |
+ | `x86_64-rumprun-netbsd`       |  ✓  |     |     | 64-bit NetBSD Rump Kernel  |
+ | `x86_64-unknown-freebsd`      |  ✓  |  ✓  |  ✓  | 64-bit FreeBSD             |
+ | `x86_64-unknown-linux-musl`   |  ✓  |     |     | 64-bit Linux with MUSL     |
+ | `x86_64-unknown-netbsd`       |  ✓  |  ✓  |  ✓  | 64-bit NetBSD              |
  
  ### Tier 3
  
@@@ -82,27 -97,15 +97,15 @@@ unofficial locations
  
  |  Target                       | std |rustc|cargo| notes                      |
  |-------------------------------|-----|-----|-----|----------------------------|
- | `i686-linux-android`          |  ✓  |     |     | 32-bit x86 Android         |
  | `aarch64-linux-android`       |  ✓  |     |     | ARM64 Android              |
- | `powerpc-unknown-linux-gnu`   |  ✓  |     |     | PowerPC Linux (2.6.18+)    |
- | `powerpc64-unknown-linux-gnu` |  ✓  |     |     | PPC64 Linux (2.6.18+)      |
- |`powerpc64le-unknown-linux-gnu`|  ✓  |     |     | PPC64LE Linux (2.6.18+)    |
- |`armv7-unknown-linux-gnueabihf`|  ✓  |     |     | ARMv7 Linux (2.6.18+)      |
- | `i386-apple-ios`              |  ✓  |     |     | 32-bit x86 iOS             |
- | `x86_64-apple-ios`            |  ✓  |     |     | 64-bit x86 iOS             |
- | `armv7-apple-ios`             |  ✓  |     |     | ARM iOS                    |
- | `armv7s-apple-ios`            |  ✓  |     |     | ARM iOS                    |
- | `aarch64-apple-ios`           |  ✓  |     |     | ARM64 iOS                  |
+ | `i686-linux-android`          |  ✓  |     |     | 32-bit x86 Android         |
+ | `i686-pc-windows-msvc` (XP)   |  ✓  |     |     | Windows XP support         |
  | `i686-unknown-freebsd`        |  ✓  |  ✓  |  ✓  | 32-bit FreeBSD             |
- | `x86_64-unknown-freebsd`      |  ✓  |  ✓  |  ✓  | 64-bit FreeBSD             |
- | `x86_64-unknown-openbsd`      |  ✓  |  ✓  |     | 64-bit OpenBSD             |
- | `x86_64-unknown-netbsd`       |  ✓  |  ✓  |     | 64-bit NetBSD              |
+ | `x86_64-pc-windows-msvc` (XP) |  ✓  |     |     | Windows XP support         |
+ | `x86_64-sun-solaris`          |  ✓  |  ✓  |     | 64-bit Solaris/SunOS       |
  | `x86_64-unknown-bitrig`       |  ✓  |  ✓  |     | 64-bit Bitrig              |
  | `x86_64-unknown-dragonfly`    |  ✓  |  ✓  |     | 64-bit DragonFlyBSD        |
- | `x86_64-rumprun-netbsd`       |  ✓  |     |     | 64-bit NetBSD Rump Kernel  |
- | `x86_64-sun-solaris`          |  ✓  |  ✓  |     | 64-bit Solaris/SunOS       |
- | `i686-pc-windows-msvc` (XP)   |  ✓  |     |     | Windows XP support         |
- | `x86_64-pc-windows-msvc` (XP) |  ✓  |     |     | Windows XP support         |
+ | `x86_64-unknown-openbsd`      |  ✓  |  ✓  |     | 64-bit OpenBSD             |
  
  Note that this table can be expanded over time, this isn't the exhaustive set of
  tier 3 platforms that will ever be!
@@@ -575,12 -578,8 +578,12 @@@ look something like this
  name = "hello_world"
  version = "0.1.0"
  authors = ["Your Name <you@example.com>"]
 +
 +[dependencies]
  ```
  
 +Do not worry about the `[dependencies]` line, we will come back to it later.
 +
  Cargo has populated *Cargo.toml* with reasonable defaults based on the arguments
  you gave it and your `git` global configuration. You may notice that Cargo has
  also initialized the `hello_world` directory as a `git` repository.