### What does this PR try to resolve?

This is a follow up to rust-lang#17230 which flattened `src/cargo` into `src/`.
Now we're flattening and re-arranging within what is left, including:
- `src/ops` more consistently have a `cargo_` prefix (always trips me up
guessing which way a file is)
- `src/core/resolver` -> `src/resolver`
- `src/core/compiler` -> `src/compiler`
- `src/core` -> `src/workspace`
- `src/util/toml` -> `src/workspace/parser`
- `src/util/toml_mut` -> `src/workspace/editor`
- `src/util/context` -> `src/context`
- I already had to adjust imports to make the move cleaner, so I went
ahead and shuffled those items around

Things not done
- Finding a proper home for
`src/workspace/{gc,global_cache_tracker,shell}.rs`
- Finer re-arrangements within any of these, particularly
`src/compiler`, requires deeper inspection
- Splitting a `config` out of `context`, may require deeper refactors

### How to test and review this PR?

See zulip thread: [#t-cargo > Re-organizing the Cargo
repo](https://rust-lang.zulipchat.com/#narrow/channel/246057-t-cargo/topic/Re-organizing.20the.20Cargo.20repo/with/611362033)

Update cargo submodule

29 commits in 59800466c5c41c444d264b1010b4d57e85a7117f..3efb1f477e99b42974b982d939fd100303cdf7db
2026-07-07 15:52:22 +0000 to 2026-07-17 23:53:19 +0000
- refactor(context): normalize in `homedir` instead (rust-lang/cargo#17222)
- chore(ci): reflect doc folder move in book deployment (rust-lang/cargo#17235)
- refactor(ops): Have cargo-metadata's ops match the command name (rust-lang/cargo#17233)
- chore: Flatten src (rust-lang/cargo#17231)
- chore: Flatten `src` (rust-lang/cargo#17230)
- chore(ci): remove stale libsecret packages (rust-lang/cargo#17229)
- perf: Lazily initialize git2 fetch transports  (rust-lang/cargo#17226)
- test(trim-paths): re-enable lldb debugger tests  (rust-lang/cargo#17223)
- Include SBOM outputs in fingerprints (rust-lang/cargo#17216)
- Update cfg_aliases to 0.2.2 (rust-lang/cargo#17225)
- test(trim-paths): exercise GDB on windows-gnu (rust-lang/cargo#17221)
- feat(profile): Disable incremental compilation under CI by default (rust-lang/cargo#17220)
- Remove myself from review rotation (rust-lang/cargo#17219)
- Fix typo in comment in sync (rust-lang/cargo#17217)
- docs(ref): Improve handing of built-in profiles (rust-lang/cargo#17213)
- fix: dont apply host-config gating to stable behavior (rust-lang/cargo#17198)
- chore(deps): update msrv (rust-lang/cargo#17192)
- test: fix race in cargo_compile_with_invalid_code_in_deps (rust-lang/cargo#17203)
- Rename `-Zno-embed-metadata` to `-Zembed-metadata=no` (rust-lang/cargo#17149)
- fix(source): incorrect duplicate package warning (rust-lang/cargo#17204)
- Fix manifest schema generation: `TomlDebugInfo` enum-variants doesn't renamed (rust-lang/cargo#17202)
- Reduce library search path length in new build dir layout (rust-lang/cargo#17191)
- fix(install): Move --debug to Compilation options (rust-lang/cargo#17199)
- chore(ci): dogfood `build.warnings` (rust-lang/cargo#17195)
- docs(lints): Better match clippy in lint section titles (rust-lang/cargo#17190)
- chore: bump to 0.100.0; update changelog (rust-lang/cargo#17189)
- docs(ref): Clarify MSRV for lints (rust-lang/cargo#17184)
- docs(report): add missing entry for `cargo report future-incompatibilities` (rust-lang/cargo#17188)
- Reduce rustc `-L` args used in the new `build-dir` layout (rust-lang/cargo#17168)

Update cargo submodule

29 commits in 59800466c5c41c444d264b1010b4d57e85a7117f..3efb1f477e99b42974b982d939fd100303cdf7db
2026-07-07 15:52:22 +0000 to 2026-07-17 23:53:19 +0000
- refactor(context): normalize in `homedir` instead (rust-lang/cargo#17222)
- chore(ci): reflect doc folder move in book deployment (rust-lang/cargo#17235)
- refactor(ops): Have cargo-metadata's ops match the command name (rust-lang/cargo#17233)
- chore: Flatten src (rust-lang/cargo#17231)
- chore: Flatten `src` (rust-lang/cargo#17230)
- chore(ci): remove stale libsecret packages (rust-lang/cargo#17229)
- perf: Lazily initialize git2 fetch transports  (rust-lang/cargo#17226)
- test(trim-paths): re-enable lldb debugger tests  (rust-lang/cargo#17223)
- Include SBOM outputs in fingerprints (rust-lang/cargo#17216)
- Update cfg_aliases to 0.2.2 (rust-lang/cargo#17225)
- test(trim-paths): exercise GDB on windows-gnu (rust-lang/cargo#17221)
- feat(profile): Disable incremental compilation under CI by default (rust-lang/cargo#17220)
- Remove myself from review rotation (rust-lang/cargo#17219)
- Fix typo in comment in sync (rust-lang/cargo#17217)
- docs(ref): Improve handing of built-in profiles (rust-lang/cargo#17213)
- fix: dont apply host-config gating to stable behavior (rust-lang/cargo#17198)
- chore(deps): update msrv (rust-lang/cargo#17192)
- test: fix race in cargo_compile_with_invalid_code_in_deps (rust-lang/cargo#17203)
- Rename `-Zno-embed-metadata` to `-Zembed-metadata=no` (rust-lang/cargo#17149)
- fix(source): incorrect duplicate package warning (rust-lang/cargo#17204)
- Fix manifest schema generation: `TomlDebugInfo` enum-variants doesn't renamed (rust-lang/cargo#17202)
- Reduce library search path length in new build dir layout (rust-lang/cargo#17191)
- fix(install): Move --debug to Compilation options (rust-lang/cargo#17199)
- chore(ci): dogfood `build.warnings` (rust-lang/cargo#17195)
- docs(lints): Better match clippy in lint section titles (rust-lang/cargo#17190)
- chore: bump to 0.100.0; update changelog (rust-lang/cargo#17189)
- docs(ref): Clarify MSRV for lints (rust-lang/cargo#17184)
- docs(report): add missing entry for `cargo report future-incompatibilities` (rust-lang/cargo#17188)
- Reduce rustc `-L` args used in the new `build-dir` layout (rust-lang/cargo#17168)