Add regression test for -Zcrate-attr in rustdoc --test

tests/rustdoc-ui/doctest/unstable-opts-143930.rs

@@ -0,0 +1,14 @@
+// This test verifies that unstable options like `-Zcrate-attr` are respected when `--test` is
+// passed.
+//
+// <https://github.com/rust-lang/rust/issues/143930>
+//
+// NOTE: If any of these command line arguments or features get stabilized, please replace with
+// another unstable one.
+
+//@ check-pass
+//@ normalize-stdout: "finished in \d+\.\d+s" -> "finished in $$TIME"
+//@ compile-flags: --test -Zcrate-attr=feature(register_tool) -Zcrate-attr=register_tool(rapx)
+
+#[rapx::tag]
+fn f() {}

tests/rustdoc-ui/doctest/unstable-opts-143930.stdout

@@ -0,0 +1,5 @@
+
+running 0 tests
+
+test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in $TIME
+

tests/rustdoc-ui/doctest/unstable-opts-147276.crate_attr.stdout

@@ -0,0 +1,5 @@
+
+running 0 tests
+
+test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in $TIME
+

tests/rustdoc-ui/doctest/unstable-opts-147276.normal.stderr

@@ -0,0 +1,13 @@
+error[E0658]: `#[used(linker)]` is currently unstable
+  --> $DIR/unstable-opts-147276.rs:15:1
+   |
+LL | #[used(linker)]
+   | ^^^^^^^^^^^^^^^
+   |
+   = note: see issue #93798 <https://github.com/rust-lang/rust/issues/93798> for more information
+   = help: add `#![feature(used_with_arg)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0658`.

tests/rustdoc-ui/doctest/unstable-opts-147276.rs

@@ -0,0 +1,17 @@
+// This test verifies that unstable options like `-Zcrate-attr` are respected when `--test` is
+// passed.
+//
+// <https://github.com/rust-lang/rust/issues/147276>
+//
+// NOTE: If any of these command line arguments or features get stabilized, please replace with
+// another unstable one.
+
+//@ revisions: normal crate_attr
+//@ compile-flags: --test
+//@ normalize-stdout: "finished in \d+\.\d+s" -> "finished in $$TIME"
+//@[crate_attr] check-pass
+//@[crate_attr] compile-flags: -Zcrate-attr=feature(used_with_arg)
+
+#[used(linker)]
+//[normal]~^ ERROR `#[used(linker)]` is currently unstable
+static REPRO: isize = 1;