Rollup merge of rust-lang#89508 - jhpratt:stabilize-const_panic, r=joshtriplett

Stabilize `const_panic`

Closes rust-lang#51999

FCP completed in rust-lang#89006

```@rustbot``` label +A-const-eval +A-const-fn +T-lang

cc ```@oli-obk``` for review (not `r?`'ing as not on lang team)

Author: workingjubilee

compiler/rustc_borrowck/src/lib.rs

@@ -2,7 +2,7 @@
 
 #![feature(bool_to_option)]
 #![feature(box_patterns)]
-#![feature(const_panic)]
+#![cfg_attr(bootstrap, feature(const_panic))]
 #![feature(crate_visibility_modifier)]
 #![feature(format_args_capture)]
 #![feature(in_band_lifetimes)]

compiler/rustc_const_eval/src/transform/check_consts/check.rs

@@ -887,8 +887,6 @@ impl Visitor<'tcx> for Checker<'mir, 'tcx> {
 
                 // At this point, we are calling a function, `callee`, whose `DefId` is known...
                 if is_lang_panic_fn(tcx, callee) {
-                    self.check_op(ops::Panic);
-
                     // `begin_panic` and `panic_display` are generic functions that accept
                     // types other than str. Check to enforce that only str can be used in
                     // const-eval.