…Denton

test-infra: improve compiletest and run-make-support symlink handling

I was trying to implement rust-lang#134656 to port `tests/run-make/incr-add-rust-src-component.rs`, but found some blockers related to symlink handling, so in this PR I tried to resolve them by improving symlink handling in compiletest and run-make-support (particularly for native windows msvc environment).

Key changes:

- I needed to copy symlinks (duplicate a symlink pointing to the same file), so I pulled out the copy symlink logic and re-exposed it as `run_make_support::rfs::copy_symlink`. This helper correctly accounts for the Windows symlink-to-file vs symlink-to-dir distinction (hereafter "Windows symlinks") when copying symlinks.
- `recursive_remove`:
    - I needed a way to remove symlinks themselves (no symlink traversal). `std::fs::remove_dir_all` handles them, but only if the root path is a directory. So I wrapped `std::fs::remove_dir_all` to also handle when the root path is a non-directory entity (e.g. file or symlink). Again, this properly accounts for Windows symlinks.
    - I wanted to use this for both compiletest and run-make-support, so I put the implementation and accompanying tests in `build_helper`.
    - In this sense, it's a reland of rust-lang#129302 with proper test coverage.
    - It's a thin wrapper around `std::fs::remove_dir_all` (`remove_dir_all` correctly handles read-only entries on Windows). The helper has additional permission-setting logic for when the root path is a non-dir entry on Windows to handle read-only non-dir entry.

Fixes rust-lang#126334.

Rollup merge of rust-lang#134659 - jieyouxu:recursive-remove, r=ChrisDenton

test-infra: improve compiletest and run-make-support symlink handling

I was trying to implement rust-lang#134656 to port `tests/run-make/incr-add-rust-src-component.rs`, but found some blockers related to symlink handling, so in this PR I tried to resolve them by improving symlink handling in compiletest and run-make-support (particularly for native windows msvc environment).

Key changes:

- I needed to copy symlinks (duplicate a symlink pointing to the same file), so I pulled out the copy symlink logic and re-exposed it as `run_make_support::rfs::copy_symlink`. This helper correctly accounts for the Windows symlink-to-file vs symlink-to-dir distinction (hereafter "Windows symlinks") when copying symlinks.
- `recursive_remove`:
    - I needed a way to remove symlinks themselves (no symlink traversal). `std::fs::remove_dir_all` handles them, but only if the root path is a directory. So I wrapped `std::fs::remove_dir_all` to also handle when the root path is a non-directory entity (e.g. file or symlink). Again, this properly accounts for Windows symlinks.
    - I wanted to use this for both compiletest and run-make-support, so I put the implementation and accompanying tests in `build_helper`.
    - In this sense, it's a reland of rust-lang#129302 with proper test coverage.
    - It's a thin wrapper around `std::fs::remove_dir_all` (`remove_dir_all` correctly handles read-only entries on Windows). The helper has additional permission-setting logic for when the root path is a non-dir entry on Windows to handle read-only non-dir entry.

Fixes rust-lang#126334.

…llaumeGomez

Rollup of 4 pull requests

Successful merges:

 - rust-lang#134656 (Migrate `incr-add-rust-src-component` to rmake)
 - rust-lang#134664 (Account for removal of multiline span in suggestion)
 - rust-lang#134772 (Improve/cleanup rustdoc code)
 - rust-lang#134781 (Add more `begin_panic` normalizations to panic backtrace tests)

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

Rollup merge of rust-lang#134656 - jieyouxu:migrate-incr-add-rust-src-component, r=wesleywiser

Migrate `incr-add-rust-src-component` to rmake

This PR partially supersedes rust-lang#128562, and ports the Makefile-based `tests/run-make/incr-add-rust-src-component` to use rmake.rs infra.

Part of rust-lang#121876.

This run-make test is a regression test for rust-lang#70924. It (tries to) checks that if we add the `rust-src` component in between two incremental compiles, that the compiler doesn't ICE on the second invocation.

- Original issue:rust-lang#70924
- Fix PR: rust-lang#72767
- PR adding this regression test: rust-lang#72952

However, the Makefile version of this used `$SYSROOT/lib/rustlib/src/rust/src/libstd/lib.rs`, but that actually got moved around and reorganized over the years. As of Dec 2024, the `rust-src` component is more like (specific for our purposes):

```
$SYSROOT/lib/rustlib/src/rust/
    library/std/src/lib.rs
    src/
```

However, this run-make test is ancient and it exercises incr-comp system logic. I'm not sure if this test would actually catch the original regression.

This PR was co-authored with `@Oneirical.`

r? incremental

try-job: i686-msvc
try-job: x86_64-mingw-1
try-job: x86_64-msvc
try-job: aarch64-apple

…-component, r=wesleywiser

Migrate `incr-add-rust-src-component` to rmake

This PR partially supersedes rust-lang#128562, and ports the Makefile-based `tests/run-make/incr-add-rust-src-component` to use rmake.rs infra.

Part of rust-lang#121876.

This run-make test is a regression test for rust-lang#70924. It (tries to) checks that if we add the `rust-src` component in between two incremental compiles, that the compiler doesn't ICE on the second invocation.

- Original issue:rust-lang#70924
- Fix PR: rust-lang#72767
- PR adding this regression test: rust-lang#72952

However, the Makefile version of this used `$SYSROOT/lib/rustlib/src/rust/src/libstd/lib.rs`, but that actually got moved around and reorganized over the years. As of Dec 2024, the `rust-src` component is more like (specific for our purposes):

```
$SYSROOT/lib/rustlib/src/rust/
    library/std/src/lib.rs
    src/
```

However, this run-make test is ancient and it exercises incr-comp system logic. I'm not sure if this test would actually catch the original regression.

This PR was co-authored with `@Oneirical.`

r? incremental

try-job: i686-msvc
try-job: x86_64-mingw-1
try-job: x86_64-msvc
try-job: aarch64-apple

…llaumeGomez

Rollup of 4 pull requests

Successful merges:

 - rust-lang#134656 (Migrate `incr-add-rust-src-component` to rmake)
 - rust-lang#134664 (Account for removal of multiline span in suggestion)
 - rust-lang#134772 (Improve/cleanup rustdoc code)
 - rust-lang#134781 (Add more `begin_panic` normalizations to panic backtrace tests)

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