Support MIPS/MIPS64 hosts

[xen0n]

Rust's support for MIPS is getting close to mature, with the recent addition of cross-compiled MIPS host compilers it's about time we supported MIPS as a viable host platform. Here's my TODO list for that, as both a reminder for myself and hint for any future porting efforts.

• MIPS-specific: proper endianness handling (done, Correctly "detect" host endianness on MIPS #802)
• Probe for MIPS64 n64 triples (done, Support probing MIPS64 n64 targets #815)
• Wait for a libc release (0.2.18 released)
• Bump libc dep in rustup (done, Update libc for MIPS64 host builds #847)
• Add MIPS artifacts to channel manifest (been the case since 2016-11-17)
• Update rustup-init.sh (done, Support MIPS architectures in rustup-init.sh #825)
• Update related CI configs (not actionable by myself)
• Update www/rustup.js to include Linux mips and Linux mips64 UA sniffing after confirming everything works (www: MIPS support and cleanups #866)

[xen0n]

Oh, and also CI support. I think this needs input from Rust maintainers.

EDIT: I believe it's being worked on #797, but seems low-priority indeed.

[xen0n]

MIPS hosts are appearing since the 2016-11-17 nightly and beta, successfully installed with local-built rustup. Seems we only have to wait for libc 0.2.18 before the next Rust release.

[xen0n]

Considered complete! Only have to wait for the next rustup release which should have the MIPS binaries correctly produced. Closing.

[xwafish]

HI, why rust still not work on mips64el ?

curl https://sh.rustup.rs -sSf | sh
info: downloading installer
curl: (22) The requested URL returned error: 404 Not Found
rustup: command failed: curl -sSfL https://static.rust-lang.org/rustup/dist/mips64el-unknown-linux-gnuabi64/rustup-init -o /tmp/tmp.jZ6IYwI0sA/rustup-init

Thank you.

[gnzlbg]

@xen0n I am trying to use an MSA intrinsics with MIPS/MIPS64 without any luck, did you managed to do that?