Modify panic message for `assert_eq!`, `assert_ne!`, the currently unstable `assert_matches!`, as well as the corresponding `debug_assert_*` macros.
```rust
assert_eq!(1 + 1, 3);
assert_eq!(1 + 1, 3, "my custom message value={}!", 42);
```
```plain
thread 'main' panicked at $DIR/main.rs:6:5:
assertion failed: `(left == right)`
left: `2`,
right: `3`
```
```plain
thread 'main' panicked at $DIR/main.rs:6:5:
assertion failed: `(left == right)`
left: `2`,
right: `3`: my custom message value=42!
```
```plain
thread 'main' panicked at $DIR/main.rs:6:5:
assertion `left == right` failed
left: 2
right: 3
```
```plain
thread 'main' panicked at $DIR/main.rs:6:5:
assertion `left == right` failed: my custom message value=42!
left: 2
right: 3
```
This PR is a simpler subset of the #111030, but it does NOT stringify the original left and right source code assert expressions, thus should be faster to compile.
