Consider column information for `dbg!` (matching 1.76.0's)

[ojeda]

In the kernel, the std_vendor.rs file contains some functionality that comes from std. In Rust 1.76.0, rust-lang/rust#114962 got merged. This issue is about researching whether updating dbg! to match upstream with the column information would make sense for the kernel as well. For instance, it would be interesting to double-check whether the formatting optimizations apply as expected in the kernel (if not, please create an issue about it). Please submit a patch to the mailing list with the dbg! update, perhaps as an RFC, explaining your findings and why the column information would be useful (or not), similar to what was done in Rust upstream.

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This requires submitting a proper patch to the LKML and the Rust for Linux mailing list. Please recall to test your changes (including generating the documentation if changed, running the Rust doctests if changed, etc.), to use a proper title for the commit, to sign your commit under the Developer's Certificate of Origin and to add a Link: tag to this issue. Please see https://rust-for-linux.com/contributing for details.

Please take this issue only if you are new to the kernel development process and you would like to use it as a test to submit your first patch to the kernel. Please do not take it if you do not plan to make other contributions to the kernel.