Auto merge of #127912 - joboet:tls_dtor_thread_current, r=cuviper

std: make `thread::current` available in all `thread_local!` destructors

... and thereby allow the panic runtime to always print the right thread name.

This works by modifying the TLS destructor system to schedule a runtime cleanup function after all other TLS destructors registered by `std` have run. Unfortunately, this doesn't affect foreign TLS destructors, `thread::current` will still panic there.

Additionally, the thread ID returned by `current_id` will now always be available, even inside the global allocator, and will not change during the lifetime of one thread (this was previously the case with key-based TLS).

The mechanisms I added for this (`local_pointer` and `thread_cleanup`) will also allow finally fixing #111272 by moving the signal stack to a similar runtime-cleanup TLS variable.

Author: bors

tests/fail/tail_calls/cc-mismatch.stderr

@@ -15,9 +15,9 @@ LL |     extern "rust-call" fn call_once(self, args: Args) -> Self::Output;
    = note: inside `std::panicking::r#try::<i32, &dyn std::ops::Fn() -> i32 + std::marker::Sync + std::panic::RefUnwindSafe>` at RUSTLIB/std/src/panicking.rs:LL:CC
    = note: inside `std::panic::catch_unwind::<&dyn std::ops::Fn() -> i32 + std::marker::Sync + std::panic::RefUnwindSafe, i32>` at RUSTLIB/std/src/panic.rs:LL:CC
    = note: inside closure at RUSTLIB/std/src/rt.rs:LL:CC
-   = note: inside `std::panicking::r#try::do_call::<{closure@std::rt::lang_start_internal::{closure#2}}, isize>` at RUSTLIB/std/src/panicking.rs:LL:CC
-   = note: inside `std::panicking::r#try::<isize, {closure@std::rt::lang_start_internal::{closure#2}}>` at RUSTLIB/std/src/panicking.rs:LL:CC
-   = note: inside `std::panic::catch_unwind::<{closure@std::rt::lang_start_internal::{closure#2}}, isize>` at RUSTLIB/std/src/panic.rs:LL:CC
+   = note: inside `std::panicking::r#try::do_call::<{closure@std::rt::lang_start_internal::{closure#1}}, isize>` at RUSTLIB/std/src/panicking.rs:LL:CC
+   = note: inside `std::panicking::r#try::<isize, {closure@std::rt::lang_start_internal::{closure#1}}>` at RUSTLIB/std/src/panicking.rs:LL:CC
+   = note: inside `std::panic::catch_unwind::<{closure@std::rt::lang_start_internal::{closure#1}}, isize>` at RUSTLIB/std/src/panic.rs:LL:CC
    = note: inside `std::rt::lang_start_internal` at RUSTLIB/std/src/rt.rs:LL:CC
    = note: inside `std::rt::lang_start::<()>` at RUSTLIB/std/src/rt.rs:LL:CC
 

tests/pass/backtrace/backtrace-api-v0.stderr

@@ -10,7 +10,7 @@ RUSTLIB/core/src/ops/function.rs:LL:CC (std::ops::function::impls::call_once)
 RUSTLIB/std/src/panicking.rs:LL:CC (std::panicking::r#try::do_call)
 RUSTLIB/std/src/panicking.rs:LL:CC (std::panicking::r#try)
 RUSTLIB/std/src/panic.rs:LL:CC (std::panic::catch_unwind)
-RUSTLIB/std/src/rt.rs:LL:CC (std::rt::lang_start_internal::{closure#2})
+RUSTLIB/std/src/rt.rs:LL:CC (std::rt::lang_start_internal::{closure#1})
 RUSTLIB/std/src/panicking.rs:LL:CC (std::panicking::r#try::do_call)
 RUSTLIB/std/src/panicking.rs:LL:CC (std::panicking::r#try)
 RUSTLIB/std/src/panic.rs:LL:CC (std::panic::catch_unwind)

tests/pass/backtrace/backtrace-api-v1.stderr

@@ -10,7 +10,7 @@ RUSTLIB/core/src/ops/function.rs:LL:CC (std::ops::function::impls::call_once)
 RUSTLIB/std/src/panicking.rs:LL:CC (std::panicking::r#try::do_call)
 RUSTLIB/std/src/panicking.rs:LL:CC (std::panicking::r#try)
 RUSTLIB/std/src/panic.rs:LL:CC (std::panic::catch_unwind)
-RUSTLIB/std/src/rt.rs:LL:CC (std::rt::lang_start_internal::{closure#2})
+RUSTLIB/std/src/rt.rs:LL:CC (std::rt::lang_start_internal::{closure#1})
 RUSTLIB/std/src/panicking.rs:LL:CC (std::panicking::r#try::do_call)
 RUSTLIB/std/src/panicking.rs:LL:CC (std::panicking::r#try)
 RUSTLIB/std/src/panic.rs:LL:CC (std::panic::catch_unwind)

tests/pass/backtrace/backtrace-global-alloc.stderr

@@ -14,7 +14,7 @@
  at RUSTLIB/std/src/panicking.rs:LL:CC
    7: std::panic::catch_unwind
  at RUSTLIB/std/src/panic.rs:LL:CC
-   8: std::rt::lang_start_internal::{closure#2}
+   8: std::rt::lang_start_internal::{closure#1}
  at RUSTLIB/std/src/rt.rs:LL:CC
    9: std::panicking::r#try::do_call
  at RUSTLIB/std/src/panicking.rs:LL:CC

tests/pass/backtrace/backtrace-std.stderr

@@ -22,7 +22,7 @@
  at RUSTLIB/std/src/panicking.rs:LL:CC
   11: std::panic::catch_unwind
  at RUSTLIB/std/src/panic.rs:LL:CC
-  12: std::rt::lang_start_internal::{closure#2}
+  12: std::rt::lang_start_internal::{closure#1}
  at RUSTLIB/std/src/rt.rs:LL:CC
   13: std::panicking::r#try::do_call
  at RUSTLIB/std/src/panicking.rs:LL:CC