Move /src/test to /tests

tests/rustdoc-ui/ignore-block-help.rs

@@ -0,0 +1,10 @@
+// check-pass
+
+/// ```ignore (to-prevent-tidy-error)
+/// let heart = '❤️';
+/// ```
+//~^^^ WARNING could not parse code block
+//~| NOTE on by default
+//~| NOTE character literal may only contain one codepoint
+//~| HELP `ignore` code blocks require valid Rust code
+pub struct X;