rustdoc source tests fail when remap-debuginfo is enabled

Code

#![crate_name = "foo"]

// This test ensures that the [src] link is present on traits items.

//@ has foo/trait.Iterator.html '//*[@id="method.zip"]//a[@class="src"]' "Source"
pub use std::iter::Iterator;

Reproduction Steps

./x t --stage 1 tests/rustdoc/{source-code-pages/src-links-auto-impls.rs,ensure-src-link.rs}

Expected Outcome

Test should pass.

Actual Output

failures:

---- [rustdoc] tests/rustdoc/source-code-pages/src-links-auto-impls.rs stdout ----
------python3.13 stdout------------------------------

------python3.13 stderr------------------------------
9: has check failed
        `XPATH PATTERN` did not match
        //@ has - '//*[@id="impl-Any-for-T"]//a[@class="src rightside"]' 'Source'

Encountered 1 errors

---- [rustdoc] tests/rustdoc/ensure-src-link.rs stdout ----
------python3.13 stdout------------------------------

------python3.13 stderr------------------------------
5: has check failed
	`XPATH PATTERN` did not match
	//@ has foo/trait.Iterator.html '//*[@id="method.zip"]//a[@class="src"]' "Source"

Encountered 1 errors

Version

cec70080fd441d16e9fb08a0d1d1a04c72d1ed25

Additional Details

bootstrap.toml:

profile = "compiler"
change-id = "ignore"

[build]
profiler = true
description = "by Ferrous Systems"

[llvm]
download-ci-llvm = true

[rust]
remap-debuginfo = true
channel = "beta"
lld = true
deny-warnings = false
debug-assertions = true
debug-assertions-std = true
new-symbol-mangling = true

Start by running the reproduced command against tests/rustdoc/{source-code-pages/src-links-auto-impls.rs,ensure-src-link.rs} with remap-debuginfo enabled in bootstrap.toml. Inspect the failing source-link checks and generated rustdoc output; done means both tests pass under that configuration.