Added comment to

`tests/ui/mismatched_types/assignment-mismatch-various-types.rs`

merge `tests/ui/mismatched_types/main.rs`

Author: reddevilmidzy

tests/ui/mismatched_types/assignment-mismatch-various-types.rs

@@ -1,6 +1,9 @@
+//! regression test for <https://github.com/rust-lang/rust/issues/3477>
+
 fn main() {
+    let x: u32 = ();
+    //~^ ERROR mismatched types
+
     let _p: char = 100;
     //~^ ERROR mismatched types
-    //~| NOTE expected `char`, found `u8`
-    //~| NOTE expected due to this
 }

tests/ui/mismatched_types/assignment-mismatch-various-types.stderr

@@ -1,11 +1,19 @@
 error[E0308]: mismatched types
-  --> $DIR/issue-3477.rs:2:20
+  --> $DIR/assignment-mismatch-various-types.rs:4:18
+   |
+LL |     let x: u32 = ();
+   |            ---   ^^ expected `u32`, found `()`
+   |            |
+   |            expected due to this
+
+error[E0308]: mismatched types
+  --> $DIR/assignment-mismatch-various-types.rs:7:20
    |
 LL |     let _p: char = 100;
    |             ----   ^^^ expected `char`, found `u8`
    |             |
    |             expected due to this
 
-error: aborting due to 1 previous error
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0308`.