Create ui test for -Ztreat-err-as-bug delay_span_bug

Author: spastorino

src/test/ui/treat-err-as-bug/delay_span_bug.rs

@@ -0,0 +1,11 @@
+// compile-flags: -Ztreat-err-as-bug
+// failure-status: 101
+// error-pattern: aborting due to `-Z treat-err-as-bug=1`
+// error-pattern: [trigger_delay_span_bug] trigger a delay span bug
+// normalize-stderr-test "note: .*\n\n" -> ""
+// normalize-stderr-test "thread 'rustc' panicked.*\n" -> ""
+
+#![feature(rustc_attrs)]
+
+#[rustc_error(delay_span_bug_from_inside_query)]
+fn main() {}

src/test/ui/treat-err-as-bug/delay_span_bug.stderr

@@ -0,0 +1,11 @@
+error: internal compiler error: delayed span bug triggered by #[rustc_error(delay_span_bug_from_inside_query)]
+  --> $DIR/delay_span_bug.rs:11:1
+   |
+LL | fn main() {}
+   | ^^^^^^^^^
+
+error: internal compiler error: unexpected panic
+
+query stack during panic:
+#0 [trigger_delay_span_bug] trigger a delay span bug
+end of query stack