Moved crash test to ui test

Author: jagunter

tests/crashes/140823.rs

@@ -0,0 +1,26 @@
+//! Functions with a mismatch between the expected and found type where the difference is a reference
+//! may trigger analysis for additional help. In this test the expected type will be
+//! &'a Container<&'a u8> and the found type will be Container<&'?0 u8>.
+//!
+//! This test exercises a scenario where the found type being analyzed contains an inference region
+//! variable ('?0). This cannot be used in comparisons because the variable no longer exists by the
+//! time the later analysis is performed.
+//!
+//! This is a regression test of #140823
+
+trait MyFn<P> {}
+
+struct Container<T> {
+    data: T,
+}
+
+struct Desugared {
+    callback: Box<dyn for<'a> MyFn<&'a Container<&'a u8>>>,
+}
+
+fn test(callback: Box<dyn for<'a> MyFn<Container<&'a u8>>>) -> Desugared {
+    Desugared { callback }
+    //~^ ERROR mismatched types
+}
+
+fn main() {}

tests/ui/fn/issue-140823.rs

@@ -0,0 +1,12 @@
+error[E0308]: mismatched types
+  --> $DIR/issue-140823.rs:22:17
+   |
+LL |     Desugared { callback }
+   |                 ^^^^^^^^ expected `Box<dyn MyFn<&Container<&u8>>>`, found `Box<dyn MyFn<Container<&u8>>>`
+   |
+   = note: expected struct `Box<(dyn for<'a> MyFn<&'a Container<&'a u8>> + 'static)>`
+              found struct `Box<(dyn for<'a> MyFn<Container<&'a u8>> + 'static)>`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0308`.