Rollup merge of rust-lang#140009 - ShE3py:tls-abort, r=thomcc

docs(LocalKey<T>): clarify that T's Drop shouldn't panic

Clarify that should a TLS destructor panics, the process will abort.

Also, an abort may be obfuscated as the process can be terminated with `SIGSEGV` or [`STATUS_STACK_BUFFER_OVERRUN`](https://devblogs.microsoft.com/oldnewthing/20190108-00/?p=100655) (i.e., `SIGABRT` is not guaranteed), so explicitly prints that the process was aborted.

Context:
https://users.rust-lang.org/t/status-stack-buffer-overrun-on-windows-without-any-usage-of-unsafe/128417

``@rustbot`` label -T-compiler

Author: ChrisDenton

std/src/rt.rs

@@ -46,7 +46,7 @@ macro_rules! rtprintpanic {
 macro_rules! rtabort {
     ($($t:tt)*) => {
         {
-            rtprintpanic!("fatal runtime error: {}\n", format_args!($($t)*));
+            rtprintpanic!("fatal runtime error: {}, aborting\n", format_args!($($t)*));
             crate::sys::abort_internal();
         }
     }

std/src/thread/local.rs

@@ -22,12 +22,16 @@ use crate::fmt;
 ///
 /// Initialization is dynamically performed on the first call to a setter (e.g.
 /// [`with`]) within a thread, and values that implement [`Drop`] get
-/// destructed when a thread exits. Some caveats apply, which are explained below.
+/// destructed when a thread exits. Some platform-specific caveats apply, which
+/// are explained below.
+/// Note that, should the destructor panics, the whole process will be [aborted].
 ///
 /// A `LocalKey`'s initializer cannot recursively depend on itself. Using a
 /// `LocalKey` in this way may cause panics, aborts or infinite recursion on
 /// the first call to `with`.
 ///
+/// [aborted]: crate::process::abort
+///
 /// # Single-thread Synchronization
 ///
 /// Though there is no potential race with other threads, it is still possible to