Rollup merge of #122291 - lilasta:stabilize_const_location_fields, r=dtolnay

Stabilize `const_caller_location` and `const_location_fields`

Closes #102911. Closes #76156.

tests: [library/core/tests/panic/location.rs](3521a2f2f3/library/core/tests/panic/location.rs)

API:
```rust
// core::panic::location
impl Location {
    pub const fn caller() -> &'static Location<'static>;
    pub const fn file(&self) -> &str;
    pub const fn line(&self) -> u32;
    pub const fn column(&self) -> u32;
}
```

library/core/src/lib.rs

@@ -125,7 +125,6 @@
 #![feature(const_array_into_iter_constructors)]
 #![feature(const_bigint_helper_methods)]
 #![feature(const_black_box)]
-#![feature(const_caller_location)]
 #![feature(const_cell_into_inner)]
 #![feature(const_char_from_u32_unchecked)]
 #![feature(const_eval_select)]