Rollup merge of #143622 - Gelbpunkt:mips64-unknown-linux-muslabi64-target-maintainer, r=jieyouxu

Add target maintainer information for mips64-unknown-linux-muslabi64

The `mips64-unknown-linux-muslabi64` target is currently rather broken, but I'm working on getting it fixed so that it can at least be used again.

While I can't commit to maintaining the LLVM side of this target, I don't mind looking into any other MIPS or musl-related issues that arise with this target.

See e.g. #143409 for some rustc fixes I have in the pipeline and rust-lang/libc#4509, rust-lang/libc#4527, rust-lang/libc#4528, rust-lang/libc#4529, rust-lang/libc#4530 for fixing the libc definitions for this target.

I'm adding myself as a maintainer mostly due to [this interaction](rust-lang/libc#4530 (comment)).

LLVM support has been a concern for these targets in the past, but it shouldn't hurt to have a nominal maintainer for these even if they remain tier 3. From my experience, LLVM for MIPS is working well nowadays unless you decide to use LLD, which is horribly broken on MIPS.

Author: matthiaskrgr

src/doc/rustc/src/SUMMARY.md

@@ -83,6 +83,7 @@
     - [m68k-unknown-linux-gnu](platform-support/m68k-unknown-linux-gnu.md)
     - [m68k-unknown-none-elf](platform-support/m68k-unknown-none-elf.md)
     - [mips64-openwrt-linux-musl](platform-support/mips64-openwrt-linux-musl.md)
+    - [mips64-unknown-linux-muslabi64](platform-support/mips64-unknown-linux-muslabi64.md)
     - [mipsel-sony-psx](platform-support/mipsel-sony-psx.md)
     - [mipsel-unknown-linux-gnu](platform-support/mipsel-unknown-linux-gnu.md)
     - [mips\*-mti-none-elf](platform-support/mips-mti-none-elf.md)

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

@@ -333,7 +333,7 @@ target | std | host | notes
 `mips-unknown-linux-uclibc` | ✓ |  | MIPS Linux with uClibc
 [`mips64-openwrt-linux-musl`](platform-support/mips64-openwrt-linux-musl.md) | ? |  | MIPS64 for OpenWrt Linux musl 1.2.3
 `mips64-unknown-linux-gnuabi64` | ✓ | ✓ | MIPS64 Linux, N64 ABI (kernel 4.4, glibc 2.23)
-`mips64-unknown-linux-muslabi64` | ✓ |  | MIPS64 Linux, N64 ABI, musl 1.2.3
+[`mips64-unknown-linux-muslabi64`](platform-support/mips64-unknown-linux-muslabi64.md) | ✓ | ✓ | MIPS64 Linux, N64 ABI, musl 1.2.3
 `mips64el-unknown-linux-gnuabi64` | ✓ | ✓ | MIPS64 (little endian) Linux, N64 ABI (kernel 4.4, glibc 2.23)
 `mips64el-unknown-linux-muslabi64` | ✓ |  | MIPS64 (little endian) Linux, N64 ABI, musl 1.2.3
 `mipsel-sony-psp` | * |  | MIPS (LE) Sony PlayStation Portable (PSP)

src/doc/rustc/src/platform-support/mips64-unknown-linux-muslabi64.md

@@ -0,0 +1,49 @@
+# mips64-unknown-linux-muslabi64
+
+**Tier: 3**
+
+Target for 64-bit big endian MIPS Linux programs using musl libc and the N64 ABI.
+
+## Target maintainers
+
+[@Gelbpunkt](https://github.com/Gelbpunkt)
+
+## Requirements
+
+Building the target itself requires a 64-bit big endian MIPS compiler that is
+supported by `cc-rs`.
+
+## Building the target
+
+The target can be built by enabling it for a `rustc` build.
+
+```toml
+[build]
+target = ["mips64-unknown-linux-muslabi64"]
+```
+
+Make sure your C compiler is included in `$PATH`, then add it to the
+`bootstrap.toml`:
+
+```toml
+[target.mips64-unknown-linux-muslabi64]
+cc = "mips64-linux-musl-gcc"
+cxx = "mips64-linux-musl-g++"
+ar = "mips64-linux-musl-ar"
+linker = "mips64-linux-musl-gcc"
+```
+
+## Building Rust programs
+
+Rust does not yet ship pre-compiled artifacts for this target. To compile for
+this target, you will first need to build Rust with the target enabled (see
+"Building the target" above).
+
+## Cross-compilation
+
+This target can be cross-compiled from any host.
+
+## Testing
+
+This target can be tested as normal with `x.py` on a 64-bit big endian MIPS
+host or via QEMU emulation.