Rollup merge of #72389 - Aaron1011:feature/move-fn-self-msg, r=nikomatsakis

Explain move errors that occur due to method calls involving `self`

When calling a method that takes `self` (e.g. `vec.into_iter()`), the method receiver is moved out of. If the method receiver is used again, a move error will be emitted::

```rust
fn main() {
    let a = vec![true];
    a.into_iter();
    a;
}
```

emits

```
error[E0382]: use of moved value: `a`
 --> src/main.rs:4:5
  |
2 |     let a = vec![true];
  |         - move occurs because `a` has type `std::vec::Vec<bool>`, which does not implement the `Copy` trait
3 |     a.into_iter();
  |     - value moved here
4 |     a;
  |     ^ value used here after move
```

However, the error message doesn't make it clear that the move is caused by the call to `into_iter`.

This PR adds additional messages to move errors when the move is caused by using a value as the receiver of a `self` method::

```
error[E0382]: use of moved value: `a`
   --> vec.rs:4:5
    |
2   |     let a = vec![true];
    |         - move occurs because `a` has type `std::vec::Vec<bool>`, which does not implement the `Copy` trait
3   |     a.into_iter();
    |     ------------- value moved due to this method call
4   |     a;
    |     ^ value used here after move
    |
note: this function takes `self`, which moves the receiver
   --> /home/aaron/repos/rust/src/libcore/iter/traits/collect.rs:239:5
    |
239 |     fn into_iter(self) -> Self::IntoIter;
```

TODO:

- [x] Add special handling for `FnOnce/FnMut/Fn` - we probably don't want to point at the unstable trait methods
- [x] Consider adding additional context for operations (e.g. `Shr::shr`) when the call was generated using the operator syntax (e.g. `a >> b`)
- [x] Consider pointing to the method parent (impl or trait block) in addition to the method itself.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/librustc_mir/transform/const_prop.rs b/src/librustc_mir/transform/const_prop.rs
index 0ff60cbd55d..72db35de408 100644
--- a/src/librustc_mir/transform/const_prop.rs
+++ b/src/librustc_mir/transform/const_prop.rs
@@ -511,6 +511,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
             // This is basically `force_bits`.
             let r_bits = r_bits.and_then(|r| r.to_bits_or_ptr(right_size, &self.tcx).ok());
             if r_bits.map_or(false, |b| b >= left_size_bits as u128) {
+                debug!("check_binary_op: reporting assert for {:?}", source_info);
                 self.report_assert_as_lint(
                     lint::builtin::ARITHMETIC_OVERFLOW,
                     source_info,