Move use_self_macro into crashes/auxiliary

tests/ui/crashes/auxiliary/use_self_macro.rs

@@ -0,0 +1,15 @@
+macro_rules! use_self {
+    (
+        impl $ty:ident {
+            fn func(&$this:ident) {
+                [fields($($field:ident)*)]
+            }
+        }
+    ) => (
+        impl  $ty {
+            fn func(&$this) {
+                let $ty { $($field),* } = $this;
+            }
+        }
+    )
+}

tests/ui/crashes/ice-4671.rs

@@ -1,7 +1,7 @@
 #![warn(clippy::use_self)]
 
 #[macro_use]
-#[path = "../auxiliary/use_self_macro.rs"]
+#[path = "auxiliary/use_self_macro.rs"]
 mod use_self_macro;
 
 struct Foo {