Auto merge of #117292 - estebank:issue-80446, r=davidtwco

Detect misparsed binop caused by missing semi

When encountering

```rust
foo()
*bar = baz;
```

We currently emit potentially two errors, one for the return type of
`foo` not being multiplicative by the type of `bar`, and another for
`foo() * bar` not being assignable.

We now check for this case and suggest adding a semicolon in the right
place and emit only a single error.

Fix #80446.

Author: bors