Move some rustdoc-ui tests to subdirectories

tests/rustdoc-ui/doctest/failed-doctest-output.rs

@@ -0,0 +1,28 @@
+// ignore-windows
+// There's a parallel version of this test for Windows.
+
+// Issue #51162: A failed doctest was not printing its stdout/stderr
+// FIXME: if/when the output of the test harness can be tested on its own, this test should be
+// adapted to use that, and that normalize line can go away
+
+// compile-flags:--test --test-args --test-threads=1
+// rustc-env:RUST_BACKTRACE=0
+// normalize-stdout-test: "tests/rustdoc-ui/doctest" -> "$$DIR"
+// normalize-stdout-test "finished in \d+\.\d+s" -> "finished in $$TIME"
+// failure-status: 101
+
+// doctest fails at runtime
+/// ```
+/// println!("stdout 1");
+/// eprintln!("stderr 1");
+/// println!("stdout 2");
+/// eprintln!("stderr 2");
+/// panic!("oh no");
+/// ```
+pub struct SomeStruct;
+
+// doctest fails at compile time
+/// ```
+/// no
+/// ```
+pub struct OtherStruct;