Handle nested pairs in MIR trans.

[eddyb]

Found while trying to compile the latest Servo master.

cc @shinglyu

[rust-highfive]

r? @nrc

(rust_highfive has picked a reviewer for you, use r? to override)

[dotdash]

@bors r+

[bors]

📌 Commit fe5ce97 has been approved by dotdash

[eddyb]

@bors p=1 Servo needs to rustup to a nightly with this fix for -Zorbit to work for them.

[bors]

⌛ Testing commit fe5ce97 with merge dc17348...

[bors]

☀️ Test successful - auto-linux-32-nopt-t, auto-linux-32-opt, auto-linux-64-cargotest, auto-linux-64-cross-freebsd, auto-linux-64-debug-opt, auto-linux-64-nopt-t, auto-linux-64-opt, auto-linux-64-opt-mir, auto-linux-64-opt-rustbuild, auto-linux-64-x-android-t, auto-linux-cross-opt, auto-linux-musl-64-opt, auto-mac-32-opt, auto-mac-64-opt, auto-mac-64-opt-rustbuild, auto-mac-cross-ios-opt, auto-win-gnu-32-opt, auto-win-gnu-32-opt-rustbuild, auto-win-gnu-64-opt, auto-win-msvc-32-opt, auto-win-msvc-64-cargotest, auto-win-msvc-64-opt, auto-win-msvc-64-opt-mir, auto-win-msvc-64-opt-rustbuild
Approved by: dotdash
Pushing dc173481a19f4c1e06a58506e404be9dc3d4119a to master...

[bors]

👀 Test was successful, but fast-forwarding failed: 422 Update is not a fast forward

[alexcrichton]

@bors: retry

• manually merged to master

cc @brson, I guess bors needs to be manually kicked when a manual merge happens by accident?

[bors]

⌛ Testing commit fe5ce97 with merge 3fa1cdf...

[Manishearth]

@bors p=20

(should be higher pri than the rollup, but rollup should be higher pri than everything else)

[bors]

💔 Test failed - auto-win-gnu-32-opt-rustbuild

[eddyb]

@bors retry

Looks spurious but I haven't seen this exact one before.

[bors]

⚡ Previous build results for auto-linux-64-cargotest, auto-win-msvc-64-cargotest are reusable. Rebuilding only auto-linux-32-nopt-t, auto-linux-32-opt, auto-linux-64-cross-freebsd, auto-linux-64-debug-opt, auto-linux-64-nopt-t, auto-linux-64-opt, auto-linux-64-opt-mir, auto-linux-64-opt-rustbuild, auto-linux-64-x-android-t, auto-linux-cross-opt, auto-linux-musl-64-opt, auto-mac-32-opt, auto-mac-64-opt, auto-mac-64-opt-rustbuild, auto-mac-cross-ios-opt, auto-win-gnu-32-opt, auto-win-gnu-32-opt-rustbuild, auto-win-gnu-64-opt, auto-win-msvc-32-opt, auto-win-msvc-64-opt, auto-win-msvc-64-opt-mir, auto-win-msvc-64-opt-rustbuild...

[bors]

☀️ Test successful - auto-linux-32-nopt-t, auto-linux-32-opt, auto-linux-64-cargotest, auto-linux-64-cross-freebsd, auto-linux-64-debug-opt, auto-linux-64-nopt-t, auto-linux-64-opt, auto-linux-64-opt-mir, auto-linux-64-opt-rustbuild, auto-linux-64-x-android-t, auto-linux-cross-opt, auto-linux-musl-64-opt, auto-mac-32-opt, auto-mac-64-opt, auto-mac-64-opt-rustbuild, auto-mac-cross-ios-opt, auto-win-gnu-32-opt, auto-win-gnu-32-opt-rustbuild, auto-win-gnu-64-opt, auto-win-msvc-32-opt, auto-win-msvc-64-cargotest, auto-win-msvc-64-opt, auto-win-msvc-64-opt-mir, auto-win-msvc-64-opt-rustbuild
Approved by: dotdash
Pushing 3fa1cdf to master...