add test for ICE: tcx.resolutions(()) is not supported for local crate -Zunpretty=mir on invalid module path with staged_ap

Fixes rust-lang#108697

Author: matthiaskrgr

tests/ui/unpretty/staged-api-invalid-path-108697.rs

@@ -0,0 +1,9 @@
+// issue: rust-lang/rust#108697
+// ICE: tcx.resolutions(()) is not supported for local crate -Zunpretty=mir
+// on invalid module path with staged_api
+//@ compile-flags: -Zunpretty=mir
+
+#![feature(staged_api)]
+#[path = "lol"]
+mod foo;
+//~^ ERROR couldn't read

tests/ui/unpretty/staged-api-invalid-path-108697.stderr

@@ -0,0 +1,8 @@
+error: couldn't read $DIR/lol: No such file or directory (os error 2)
+  --> $DIR/staged-api-invalid-path-108697.rs:8:1
+   |
+LL | mod foo;
+   | ^^^^^^^^
+
+error: aborting due to 1 previous error
+