Test that ReifyShim + caller_location return the def site.

Author: anp

src/test/ui/rfc-2091-track-caller/tracked-fn-ptr-with-arg.rs

@@ -8,7 +8,10 @@ fn pass_to_ptr_call<T>(f: fn(T), x: T) {
 
 #[track_caller]
 fn tracked_unit(_: ()) {
-    assert_eq!(std::panic::Location::caller().file(), file!());
+    let expected_line = line!() - 1;
+    let location = std::panic::Location::caller();
+    assert_eq!(location.file(), file!());
+    assert_eq!(location.line(), expected_line, "call shims report location as fn definition");
 }
 
 fn main() {

src/test/ui/rfc-2091-track-caller/tracked-fn-ptr.rs

@@ -8,7 +8,10 @@ fn ptr_call(f: fn()) {
 
 #[track_caller]
 fn tracked() {
-    assert_eq!(std::panic::Location::caller().file(), file!());
+    let expected_line = line!() - 1;
+    let location = std::panic::Location::caller();
+    assert_eq!(location.file(), file!());
+    assert_eq!(location.line(), expected_line, "call shims report location as fn definition");
 }
 
 fn main() {