Rollup merge of #53932 - matthewjasper:remove-base-path, r=nikomatsakis

[NLL] Remove base_place

This function was supposed to make `Box` less special. But

* I think that the consensus is that MIR borrowck is going to fully special case `Box`
* It wasn't implemented correctly, it's looking at the type of the wrong `Place`, resulting in weird behaviour:

```rust
#![feature(nll)]
type A = Box<i32>; // If this is changed to another type then this will compile.

pub fn foo(x: Box<(String, A)>) {
    let a = x.0; // This will compile if these lines are swapped
    let b = x.1;
}
```

r? @nikomatsakis

0 files changed, 0 insertions, 0 deletions