Rollup of 9 pull requests

[matthiaskrgr]

Successful merges:

• Optimize Seek::stream_len impl for File #125087 (Optimize Seek::stream_len impl for File)
• Apply unsafe_op_in_unsafe_fn to the standard library #136986 (Apply unsafe_op_in_unsafe_fn to the standard library)
• add docs and ut for bootstrap util cc-detect #137012 (add docs and ut for bootstrap util cc-detect)
• Load all builtin targets at once instead of one by one in check-cfg #137072 (Load all builtin targets at once instead of one by one in check-cfg)
• Rework name_regions to not rely on reverse scc graph for non-member-constrain usages #137102 (Rework name_regions to not rely on reverse scc graph for non-member-constrain usages)
• Don't project into NonNull when dropping a Box #137112 (Don't project into NonNull when dropping a Box)
• Add an example for std::error::Error #137114 (Add an example for std::error::Error)
• Fix test that relies on error language #137117 (Fix test that relies on error language)
• fix broken x {doc, build} core #137119 (fix broken x {doc, build} core)

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@rustbot modify labels: rollup

Create a similar rollup

[matthiaskrgr]

@bors r+ rollup=never p=5

[bors]

📌 Commit 29e62d4 has been approved by matthiaskrgr

It is now in the queue for this repository.

[bors]

⌛ Testing commit 29e62d4 with merge fffb33d...

[rust-log-analyzer]

The job dist-various-2 failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

     |
1256 |         if let Some(result) = self.inner.size() {
     |                ^^^^^^^^^^^^   ----------------- this expression has type `core::result::Result<u64, io::error::Error>`
     |                |
     |                expected `Result<u64, Error>`, found `Option<_>`
     = note: expected enum `core::result::Result<u64, io::error::Error>`
                found enum `Option<_>`

For more information about this error, try `rustc --explain E0308`.

[bors]

💔 Test failed - checks-actions