Auto merge of #88759 - Amanieu:panic_in_drop, r=nagisa,eddyb

Add -Z panic-in-drop={unwind,abort} command-line option

This PR changes `Drop` to abort if an unwinding panic attempts to escape it, making the process abort instead. This has several benefits:
- The current behavior when unwinding out of `Drop` is very unintuitive and easy to miss: unwinding continues, but the remaining drops in scope are simply leaked.
- A lot of unsafe code doesn't expect drops to unwind, which can lead to unsoundness:
  - https://github.com/servo/rust-smallvec/issues/14
  - https://github.com/bluss/arrayvec/issues/3
- There is a code size and compilation time cost to this: LLVM needs to generate extra landing pads out of all calls in a drop implementation. This can compound when functions are inlined since unwinding will then continue on to process drops in the callee, which can itself unwind, etc.
  - Initial measurements show a 3% size reduction and up to 10% compilation time reduction on some crates (`syn`).

One thing to note about `-Z panic-in-drop=abort` is that *all* crates must be built with this option for it to be sound since it makes the compiler assume that dropping `Box<dyn Any>` will never unwind.

cc https://github.com/rust-lang/lang-team/issues/97

compiler/rustc_middle/src/query/mod.rs

@@ -1167,6 +1167,10 @@ rustc_queries! {
         fatal_cycle
         desc { "query a crate's configured panic strategy" }
     }
+    query panic_in_drop_strategy(_: CrateNum) -> PanicStrategy {
+        fatal_cycle
+        desc { "query a crate's configured panic-in-drop strategy" }
+    }
     query is_no_builtins(_: CrateNum) -> bool {
         fatal_cycle
         desc { "test whether a crate has `#![no_builtins]`" }