Avoid unconditional deps from doc links

[kevin-valerio]

Fixes #158078

[rustbot]

r? @Kivooeo

rustbot has assigned @Kivooeo.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

Why was this reviewer chosen?

The reviewer was selected based on:

• Owners of files modified in this PR: compiler
• compiler expanded to 73 candidates
• Random selection from 19 candidates

[bjorn3]

CrateDepKind::Conditional is currently only used for crates that are implicitly injected by the compiler like the panic runtime and profiler runtime.

In any case can you explain why this is actually correct? In that cases does maybe_process_path_extern get called without a later process_path_extern? Is there any risk that this will cause a crate actually referenced outside of a doc comment to be loaded as conditional?

View changes since the review

[rust-log-analyzer]

The job tidy failed! Check out the build log: (web) (plain enhanced) (plain)

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

[TIMING:end] tool::Tidy { compiler: Compiler { stage: 0, host: x86_64-unknown-linux-gnu, forced_compiler: false }, target: x86_64-unknown-linux-gnu } -- 0.000
fmt check
Diff in /checkout/tests/run-make/rustdoc-doc-link-conditional-dep/rmake.rs:17:
 
     run("app").assert_stdout_equals("7").assert_stderr_not_contains("constructor ran");
 
-    llvm_nm()
-        .input(bin_name("app"))
-        .run()
-        .assert_stdout_not_contains_regex("[Tt] _*mark_ctor");
+    llvm_nm().input(bin_name("app")).run().assert_stdout_not_contains_regex("[Tt] _*mark_ctor");
 }
 
fmt: checked 6929 files
Bootstrap failed while executing `test src/tools/tidy tidyselftest --extra-checks=py,cpp,js,spellcheck`
Build completed unsuccessfully in 0:00:50

[Kivooeo]

@rustbot author

[rustbot]

Reminder, once the PR becomes ready for a review, use @rustbot ready.