unwrap_used, expect_used: accept macro result as receiver (#14575)

changelog: [`unwrap_used`, `expect_used`]: lint even when the receiver
is a macro expansion result

This also paves the way for expanding more method call lints to expanded
receivers or arguments.

Fixes rust-lang/rust-clippy#13455

tests/ui/unwrap_expect_used.rs

@@ -66,3 +66,20 @@ fn main() {
         SOME.expect("Still not three?");
     }
 }
+
+mod with_expansion {
+    macro_rules! open {
+        ($file:expr) => {
+            std::fs::File::open($file)
+        };
+    }
+
+    fn test(file: &str) {
+        use std::io::Read;
+        let mut s = String::new();
+        let _ = open!(file).unwrap(); //~ unwrap_used
+        let _ = open!(file).expect("can open"); //~ expect_used
+        let _ = open!(file).unwrap_err(); //~ unwrap_used
+        let _ = open!(file).expect_err("can open"); //~ expect_used
+    }
+}

tests/ui/unwrap_expect_used.stderr

@@ -50,5 +50,37 @@ LL |     a.expect_err("Hello error!");
    |
    = note: if this value is an `Ok`, it will panic
 
-error: aborting due to 6 previous errors
+error: used `unwrap()` on a `Result` value
+  --> tests/ui/unwrap_expect_used.rs:80:17
+   |
+LL |         let _ = open!(file).unwrap();
+   |                 ^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: if this value is an `Err`, it will panic
+
+error: used `expect()` on a `Result` value
+  --> tests/ui/unwrap_expect_used.rs:81:17
+   |
+LL |         let _ = open!(file).expect("can open");
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: if this value is an `Err`, it will panic
+
+error: used `unwrap_err()` on a `Result` value
+  --> tests/ui/unwrap_expect_used.rs:82:17
+   |
+LL |         let _ = open!(file).unwrap_err();
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: if this value is an `Ok`, it will panic
+
+error: used `expect_err()` on a `Result` value
+  --> tests/ui/unwrap_expect_used.rs:83:17
+   |
+LL |         let _ = open!(file).expect_err("can open");
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: if this value is an `Ok`, it will panic
+
+error: aborting due to 10 previous errors