Rollup of 19 pull requests

Successful merges:

 - #144400 (`tests/ui/issues/`: The Issues Strike Back [3/N])
 - #144764 ([codegen] assume the tag, not the relative discriminant)
 - #144807 (Streamline config in bootstrap)
 - #144899 (Print CGU reuse statistics in `-Zprint-mono-items`)
 - #144909 (Add new `test::print_merged_doctests_times` used by rustdoc to display more detailed time information)
 - #144912 (Resolver: introduce a conditionally mutable Resolver for (non-)speculative resolution.)
 - #144914 (Add support for `ty::Instance` path shortening in diagnostics)
 - #144931 ([win][arm64ec] Fix msvc-wholearchive for Arm64EC)
 - #144999 (coverage: Remove all unstable support for MC/DC instrumentation)
 - #145009 (A couple small changes for rust-analyzer next-solver work)
 - #145030 (GVN:  Do not flatten derefs with ProjectionElem::Index. )
 - #145042 (stdarch subtree update)
 - #145047 (move `type_check` out of `compute_regions`)
 - #145051 (Prevent name collisions with internal implementation details)
 - #145053 (Add a lot of NLL `known-bug` tests)
 - #145055 (Move metadata symbol export from exported_non_generic_symbols to exported_symbols)
 - #145057 (Clean up some resolved test regressions of const trait removals in std)
 - #145068 (Readd myself to review queue)
 - #145070 (Add minimal `armv7a-vex-v5` tier three target)

r? `@ghost`
`@rustbot` modify labels: rollup

Rollup merge of #144999 - Zalathar:remove-mcdc, r=oli-obk

coverage: Remove all unstable support for MC/DC instrumentation

Preliminary support for a partial implementation of “Modified Condition/Decision Coverage” instrumentation was added behind the unstable flag `-Zcoverage-options=mcdc` in 2024. These are the most substantial PRs involved:

- #123409
- #126733

At the time, I accepted these PRs with relatively modest scrutiny, because I did not want to stand in the way of independent work on MC/DC instrumentation. My hope was that ongoing work by interested contributors would lead to the code becoming clearer and more maintainable over time.

---

However, that MC/DC code has proven itself to be a major burden on overall maintenance of coverage instrumentation, and a major obstacle to other planned improvements, such as internal changes needed for proper support of macro expansion regions.

I have also become reluctant to accept any further MC/DC-related changes that would increase this burden.

That tension has resulted in an unhappy impasse. On one hand, the present MC/DC implementation is not yet complete, and shows little sign of being complete at an acceptable level of code quality in the foreseeable future. On the other hand, the continued existence of this partial MC/DC implementation is imposing serious maintenance burdens on every other aspect of coverage instrumentation, and is preventing some of the very improvements that would make it easier to accept expanded MC/DC support in the future.

While I know this will be disappointing to some, I think the healthy way forward is accept that I made the wrong call in accepting the current implementation, and to remove it entirely from the compiler.

Rollup of 19 pull requests

Successful merges:

 - rust-lang#144400 (`tests/ui/issues/`: The Issues Strike Back [3/N])
 - rust-lang#144764 ([codegen] assume the tag, not the relative discriminant)
 - rust-lang#144807 (Streamline config in bootstrap)
 - rust-lang#144899 (Print CGU reuse statistics in `-Zprint-mono-items`)
 - rust-lang#144909 (Add new `test::print_merged_doctests_times` used by rustdoc to display more detailed time information)
 - rust-lang#144912 (Resolver: introduce a conditionally mutable Resolver for (non-)speculative resolution.)
 - rust-lang#144914 (Add support for `ty::Instance` path shortening in diagnostics)
 - rust-lang#144931 ([win][arm64ec] Fix msvc-wholearchive for Arm64EC)
 - rust-lang#144999 (coverage: Remove all unstable support for MC/DC instrumentation)
 - rust-lang#145009 (A couple small changes for rust-analyzer next-solver work)
 - rust-lang#145030 (GVN:  Do not flatten derefs with ProjectionElem::Index. )
 - rust-lang#145042 (stdarch subtree update)
 - rust-lang#145047 (move `type_check` out of `compute_regions`)
 - rust-lang#145051 (Prevent name collisions with internal implementation details)
 - rust-lang#145053 (Add a lot of NLL `known-bug` tests)
 - rust-lang#145055 (Move metadata symbol export from exported_non_generic_symbols to exported_symbols)
 - rust-lang#145057 (Clean up some resolved test regressions of const trait removals in std)
 - rust-lang#145068 (Readd myself to review queue)
 - rust-lang#145070 (Add minimal `armv7a-vex-v5` tier three target)

r? `@ghost`
`@rustbot` modify labels: rollup

Rollup of 19 pull requests

Successful merges:

 - rust-lang#144400 (`tests/ui/issues/`: The Issues Strike Back [3/N])
 - rust-lang#144764 ([codegen] assume the tag, not the relative discriminant)
 - rust-lang#144807 (Streamline config in bootstrap)
 - rust-lang#144899 (Print CGU reuse statistics in `-Zprint-mono-items`)
 - rust-lang#144909 (Add new `test::print_merged_doctests_times` used by rustdoc to display more detailed time information)
 - rust-lang#144912 (Resolver: introduce a conditionally mutable Resolver for (non-)speculative resolution.)
 - rust-lang#144914 (Add support for `ty::Instance` path shortening in diagnostics)
 - rust-lang#144931 ([win][arm64ec] Fix msvc-wholearchive for Arm64EC)
 - rust-lang#144999 (coverage: Remove all unstable support for MC/DC instrumentation)
 - rust-lang#145009 (A couple small changes for rust-analyzer next-solver work)
 - rust-lang#145030 (GVN:  Do not flatten derefs with ProjectionElem::Index. )
 - rust-lang#145042 (stdarch subtree update)
 - rust-lang#145047 (move `type_check` out of `compute_regions`)
 - rust-lang#145051 (Prevent name collisions with internal implementation details)
 - rust-lang#145053 (Add a lot of NLL `known-bug` tests)
 - rust-lang#145055 (Move metadata symbol export from exported_non_generic_symbols to exported_symbols)
 - rust-lang#145057 (Clean up some resolved test regressions of const trait removals in std)
 - rust-lang#145068 (Readd myself to review queue)
 - rust-lang#145070 (Add minimal `armv7a-vex-v5` tier three target)

r? `@ghost`
`@rustbot` modify labels: rollup

Rollup of 19 pull requests

Successful merges:

 - rust-lang#144400 (`tests/ui/issues/`: The Issues Strike Back [3/N])
 - rust-lang#144764 ([codegen] assume the tag, not the relative discriminant)
 - rust-lang#144807 (Streamline config in bootstrap)
 - rust-lang#144899 (Print CGU reuse statistics in `-Zprint-mono-items`)
 - rust-lang#144909 (Add new `test::print_merged_doctests_times` used by rustdoc to display more detailed time information)
 - rust-lang#144912 (Resolver: introduce a conditionally mutable Resolver for (non-)speculative resolution.)
 - rust-lang#144914 (Add support for `ty::Instance` path shortening in diagnostics)
 - rust-lang#144931 ([win][arm64ec] Fix msvc-wholearchive for Arm64EC)
 - rust-lang#144999 (coverage: Remove all unstable support for MC/DC instrumentation)
 - rust-lang#145009 (A couple small changes for rust-analyzer next-solver work)
 - rust-lang#145030 (GVN:  Do not flatten derefs with ProjectionElem::Index. )
 - rust-lang#145042 (stdarch subtree update)
 - rust-lang#145047 (move `type_check` out of `compute_regions`)
 - rust-lang#145051 (Prevent name collisions with internal implementation details)
 - rust-lang#145053 (Add a lot of NLL `known-bug` tests)
 - rust-lang#145055 (Move metadata symbol export from exported_non_generic_symbols to exported_symbols)
 - rust-lang#145057 (Clean up some resolved test regressions of const trait removals in std)
 - rust-lang#145068 (Readd myself to review queue)
 - rust-lang#145070 (Add minimal `armv7a-vex-v5` tier three target)

r? `@ghost`
`@rustbot` modify labels: rollup