Add platform support docs & maintainers for *-windows-msvc

Author: wesleywiser

src/doc/rustc/src/SUMMARY.md

@@ -113,6 +113,7 @@
     - [\*-unknown-openbsd](platform-support/openbsd.md)
     - [\*-unknown-redox](platform-support/redox.md)
     - [\*-unknown-uefi](platform-support/unknown-uefi.md)
+    - [\*-unknown-windows-msvc](platform-support/windows-msvc.md)
     - [\*-uwp-windows-msvc](platform-support/uwp-windows-msvc.md)
     - [\*-wrs-vxworks](platform-support/vxworks.md)
     - [wasm32-wasip1](platform-support/wasm32-wasip1.md)

src/doc/rustc/src/platform-support.md

@@ -34,11 +34,11 @@ target | notes
 -------|-------
 [`aarch64-apple-darwin`](platform-support/apple-darwin.md) | ARM64 macOS (11.0+, Big Sur+)
 `aarch64-unknown-linux-gnu` | ARM64 Linux (kernel 4.1+, glibc 2.17+)
-`i686-pc-windows-msvc` | 32-bit MSVC (Windows 10+, Windows Server 2016+, Pentium 4) [^x86_32-floats-return-ABI] [^win32-msvc-alignment]
+[`i686-pc-windows-msvc`](platform-support/windows-msvc.md) | 32-bit MSVC (Windows 10+, Windows Server 2016+, Pentium 4) [^x86_32-floats-return-ABI] [^win32-msvc-alignment]
 `i686-unknown-linux-gnu` | 32-bit Linux (kernel 3.2+, glibc 2.17+, Pentium 4) [^x86_32-floats-return-ABI]
 [`x86_64-apple-darwin`](platform-support/apple-darwin.md) | 64-bit macOS (10.12+, Sierra+)
 [`x86_64-pc-windows-gnu`](platform-support/windows-gnu.md) | 64-bit MinGW (Windows 10+, Windows Server 2016+)
-`x86_64-pc-windows-msvc` | 64-bit MSVC (Windows 10+, Windows Server 2016+)
+[`x86_64-pc-windows-msvc`](platform-support/windows-msvc.md) | 64-bit MSVC (Windows 10+, Windows Server 2016+)
 `x86_64-unknown-linux-gnu` | 64-bit Linux (kernel 3.2+, glibc 2.17+)
 
 [^x86_32-floats-return-ABI]: Due to limitations of the C ABI, floating-point support on `i686` targets is non-compliant: floating-point return values are passed via an x87 register, so NaN payload bits can be lost. Functions with the default Rust ABI are not affected. See [issue #115567][x86-32-float-return-issue].
@@ -88,7 +88,7 @@ so Rustup may install the documentation for a similar tier 1 target instead.
 
 target | notes
 -------|-------
-`aarch64-pc-windows-msvc` | ARM64 Windows MSVC
+[`aarch64-pc-windows-msvc`](platform-support/windows-msvc.md) | ARM64 Windows MSVC
 `aarch64-unknown-linux-musl` | ARM64 Linux with musl 1.2.3
 [`aarch64-unknown-linux-ohos`](platform-support/openharmony.md) | ARM64 OpenHarmony
 `arm-unknown-linux-gnueabi` | Armv6 Linux (kernel 3.2+, glibc 2.17)

src/doc/rustc/src/platform-support/windows-msvc.md

@@ -0,0 +1,69 @@
+# `*-pc-windows-msvc`
+
+Windows MSVC targets.
+
+**Tier 1 with host tools:**
+
+- `i686-pc-windows-msvc`: Windows on 32-bit x86.
+- `x86_64-pc-windows-msvc`: Windows on 64-bit x86.
+
+**Tier 2 with host tools:**
+
+- `aarch64-pc-windows-msvc`: Windows on ARM64.
+
+## Target maintainers
+
+[@ChrisDenton](https://github.com/ChrisDenton)
+[@dpaoliello](https://github.com/dpaoliello)
+[@lambdageek](https://github.com/lambdageek)
+[@sivadeilra](https://github.com/sivadeilra)
+[@wesleywiser](https://github.com/wesleywiser)
+
+## Requirements
+
+### OS version
+
+Windows 10 or higher is required for client installs, Windows Server 2016 or higher is required for server installs.
+
+### Host tooling
+
+The minimum supported Visual Studio version is 2017 but this support is not actively tested in CI.
+It is **highly** recommended to use the latest version of VS (currently VS 2022).
+
+### Platform details
+
+These targets fully implement the Rust standard library.
+
+The `extern "C"` calling convention conforms to Microsoft's default calling convention for the given architecture: [`__cdecl`] on `i686`, [`x64`] on `x86_64` and [`ARM64`] on `aarch64`.
+
+The `*-windows-msvc` targets produce PE/COFF binaries with CodeView debuginfo, the native formats used on Windows.
+
+[`__cdecl`]: https://learn.microsoft.com/en-us/cpp/cpp/cdecl?view=msvc-170
+[`x64`]: https://learn.microsoft.com/en-us/cpp/build/x64-calling-convention?view=msvc-170
+[`ARM64`]: https://learn.microsoft.com/en-us/cpp/build/arm64-windows-abi-conventions?view=msvc-170
+
+## Building Rust programs
+
+These targets are distributed via `rustup` and can be installed via `rustup component add [--toolchain {name}] {target}`.
+
+For example, adding the 32-bit x86 target to the `nightly` toolchain:
+
+```
+rustup component add --toolchain nightly i686-pc-windows-msvc
+```
+
+or adding the ARM64 target to the active toolchain:
+
+```
+rustup component add aarch64-pc-windows-msvc
+```
+
+## Testing
+
+There are no special requirements for testing and running this target.
+
+## Cross-compilation toolchains and C code
+
+Architectural cross-compilation from one Windows host to a different Windows platform is natively supported by the MSVC toolchain provided the appropriate components are selected when using the VS Installer.
+
+Cross-compilation from a non-Windows host to a `*-windows-msvc` target _may_ be possible but is not supported.