Auto merge of #36024 - japaric:mips64, r=alexcrichton

add mips64-gnu and mips64el-gnu targets

With this commit one can build no_core (and probably no_std as well)
Rust programs for these targets. It's not yet possible to cross compile
std for these targets because rust-lang/libc doesn't know about the
mips64 architecture.

These targets have been tested by cross compiling the "smallest hello"
program (see code below) and then running it under QEMU.

``` rust

extern {
    fn puts(_: *const u8);
}

fn start(_: isize, _: *const *const u8) -> isize {
    unsafe {
        let msg = b"Hello, world!\0";
        puts(msg as *const _ as *const u8);
    }
    0
}

trait Copy {}

trait Sized {}
```

cc #36015
r? @alexcrichton
cc @brson

The cabi stuff is likely wrong. I just copied cabi_mips source and changed some `4`s to `8`s and `32`s to `64`s. It was enough to get libc's `puts` to work but I'd like someone familiar with this module to check it.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/liballoc_system/lib.rs b/src/liballoc_system/lib.rs
index 9eade937bfb..2c0c6d068ca 100644
--- a/src/liballoc_system/lib.rs
+++ b/src/liballoc_system/lib.rs
@@ -32,7 +32,8 @@
               target_arch = "asmjs")))]
 const MIN_ALIGN: usize = 8;
 #[cfg(all(any(target_arch = "x86_64",
-              target_arch = "aarch64")))]
+              target_arch = "aarch64",
+              target_arch = "mips64")))]
 const MIN_ALIGN: usize = 16;
 
 #[no_mangle]