tests: remove ignore directives from tests that mention core/alloc/std spans.

src/test/ui/recursion/recursive-types-are-not-uninhabited.rs

@@ -1,8 +1,3 @@
-// FIXME: missing sysroot spans (#53081)
-// ignore-i586-unknown-linux-gnu
-// ignore-i586-unknown-linux-musl
-// ignore-i686-unknown-linux-musl
-
 struct R<'a> {
     r: &'a R<'a>,
 }

src/test/ui/recursion/recursive-types-are-not-uninhabited.stderr

@@ -1,5 +1,5 @@
 error[E0005]: refutable pattern in local binding: `Err(_)` not covered
-  --> $DIR/recursive-types-are-not-uninhabited.rs:11:9
+  --> $DIR/recursive-types-are-not-uninhabited.rs:6:9
    |
 LL |     let Ok(x) = res;
    |         ^^^^^ pattern `Err(_)` not covered