Add some parallelism before TyCtxt

[Zoxc]

Blocked on rust-lang/rustc-rayon#4.

r? @Mark-Simulacrum

[rust-highfive]

The job x86_64-gnu-llvm-7 of your PR failed (pretty log, raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

2020-01-07T06:30:41.0799674Z ##[command]git remote add origin https://github.com/rust-lang/rust
2020-01-07T06:30:41.0813532Z ##[command]git config gc.auto 0
2020-01-07T06:30:41.0816831Z ##[command]git config --get-all http.https://github.com/rust-lang/rust.extraheader
2020-01-07T06:30:41.0820428Z ##[command]git config --get-all http.proxy
2020-01-07T06:30:41.0824467Z ##[command]git -c http.extraheader="AUTHORIZATION: basic ***" fetch --force --tags --prune --progress --no-recurse-submodules --depth=2 origin +refs/heads/*:refs/remotes/origin/* +refs/pull/67965/merge:refs/remotes/pull/67965/merge
---
2020-01-07T06:33:34.2964768Z ########################################                                  56.5%
2020-01-07T06:33:34.3552198Z ############################################################              84.0%
2020-01-07T06:33:34.3552400Z ######################################################################## 100.0%
2020-01-07T06:33:34.6571275Z extracting /checkout/obj/build/cache/2019-12-18/rustfmt-nightly-x86_64-unknown-linux-gnu.tar.gz
2020-01-07T06:33:34.7262909Z     Updating git repository `https://github.com/Zoxc/rayon.git`
---
2020-01-07T06:36:57.5663635Z tidy check
2020-01-07T06:36:59.2021018Z * 588 error codes
2020-01-07T06:36:59.2021185Z * highest error code: E0745
2020-01-07T06:36:59.6208033Z * 275 features
2020-01-07T06:37:00.3576084Z invalid source: "git+https://github.com/Zoxc/rayon.git?branch=single-lifetime-scope#f5d9d8b52dbfc64728d3a42ed3f7292e2eb6ee6b"
2020-01-07T06:37:00.6503019Z Found 486 error codes
2020-01-07T06:37:00.6504157Z Found 0 error codes with no tests
2020-01-07T06:37:00.6504240Z Done!
2020-01-07T06:37:00.6504294Z some tidy checks failed
2020-01-07T06:37:00.6504294Z some tidy checks failed
2020-01-07T06:37:00.6511032Z 
2020-01-07T06:37:00.6511272Z 
2020-01-07T06:37:00.6512314Z command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-tools-bin/tidy" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-tools-bin/tidy" "/checkout/src" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo" "--no-vendor"
2020-01-07T06:37:00.6512717Z 
2020-01-07T06:37:00.6512831Z 
2020-01-07T06:37:00.6522453Z failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test src/tools/tidy
2020-01-07T06:37:00.6522535Z Build completed unsuccessfully in 0:01:39
2020-01-07T06:37:00.6522535Z Build completed unsuccessfully in 0:01:39
2020-01-07T06:37:00.6572914Z == clock drift check ==
2020-01-07T06:37:00.6585512Z   local time: Tue Jan  7 06:37:00 UTC 2020
2020-01-07T06:37:00.9387522Z   network time: Tue, 07 Jan 2020 06:37:00 GMT
2020-01-07T06:37:00.9387656Z == end clock drift check ==
2020-01-07T06:37:01.6911751Z 
2020-01-07T06:37:01.7033365Z ##[error]Bash exited with code '1'.
2020-01-07T06:37:01.7067686Z ##[section]Starting: Checkout
2020-01-07T06:37:01.7069356Z ==============================================================================
2020-01-07T06:37:01.7069412Z Task         : Get sources
2020-01-07T06:37:01.7069460Z Description  : Get sources from a repository. Supports Git, TfsVC, and SVN repositories.

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)

[bors]

☔ The latest upstream changes (presumably #67988) made this pull request unmergeable. Please resolve the merge conflicts.

[nikomatsakis]

Closing this pull request as Zoxc is stepping back from compiler development; see rust-lang/team#316.