Cleanup debuginfo generation a bit

[bjorn3]

This removes an no longer necessary hack. This also uses CrateDebugContext in favor of CodegenCx in debuginfo generation.

[rust-highfive]

r? @estebank

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[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.

2020-02-08T17:14:48.1320188Z ========================== Starting Command Output ===========================
2020-02-08T17:14:48.1341636Z [command]/bin/bash --noprofile --norc /home/vsts/work/_temp/0a522f6d-2d91-406c-bc61-1ac7ef346503.sh
2020-02-08T17:14:48.1551794Z 
2020-02-08T17:14:48.1613500Z ##[section]Finishing: Disable git automatic line ending conversion
2020-02-08T17:14:48.1619786Z ##[section]Starting: Checkout rust-lang/rust@refs/pull/68959/merge to s
2020-02-08T17:14:48.1621451Z Task         : Get sources
2020-02-08T17:14:48.1621480Z Description  : Get sources from a repository. Supports Git, TfsVC, and SVN repositories.
2020-02-08T17:14:48.1621510Z Version      : 1.0.0
2020-02-08T17:14:48.1621554Z Author       : Microsoft
---
2020-02-08T17:14:49.0057694Z ##[command]git remote add origin https://github.com/rust-lang/rust
2020-02-08T17:14:49.0134702Z ##[command]git config gc.auto 0
2020-02-08T17:14:49.0211378Z ##[command]git config --get-all http.https://github.com/rust-lang/rust.extraheader
2020-02-08T17:14:49.0427355Z ##[command]git config --get-all http.proxy
2020-02-08T17:14:49.0609620Z ##[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/68959/merge:refs/remotes/pull/68959/merge

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)

[mark-i-m]

cc @eddyb I think

[bors]

☔ The latest upstream changes (presumably #68975) made this pull request unmergeable. Please resolve the merge conflicts.

[JohnCSimon]

ping from triage: @bjorn3 can you address the failed checks?

[bjorn3]

This changes several files that will also be changed by #68965.

@rustbot modify labels: +S-blocked

[Dylan-DPC-zz]

This is blocked on another blocked pr, and neither of them seem to be moving in the near future, so closing this one. You can create a new PR later if you wish once there's some progress. Thanks