Rollup merge of #133420 - thesummer:rtems-unwind, r=workingjubilee

Switch rtems target to panic unwind

Switch the RTEMS target to `panic_unwind`.

Relates to rust-lang/backtrace-rs#682

Author: matthiaskrgr

compiler/rustc_target/src/spec/targets/armv7_rtems_eabihf.rs

@@ -23,7 +23,7 @@ pub(crate) fn target() -> Target {
             linker_flavor: LinkerFlavor::Gnu(Cc::Yes, Lld::No),
             linker: None,
             relocation_model: RelocModel::Static,
-            panic_strategy: PanicStrategy::Abort,
+            panic_strategy: PanicStrategy::Unwind,
             features: "+thumb2,+neon,+vfp3".into(),
             max_atomic_width: Some(64),
             emit_debug_gdb_scripts: false,

library/panic_unwind/src/lib.rs

@@ -46,7 +46,7 @@ cfg_if::cfg_if! {
         target_os = "psp",
         target_os = "xous",
         target_os = "solid_asp3",
-        all(target_family = "unix", not(any(target_os = "espidf", target_os = "rtems", target_os = "nuttx"))),
+        all(target_family = "unix", not(any(target_os = "espidf", target_os = "nuttx"))),
         all(target_vendor = "fortanix", target_env = "sgx"),
         target_family = "wasm",
     ))] {

library/std/src/sys/personality/mod.rs

@@ -31,7 +31,7 @@ cfg_if::cfg_if! {
         target_os = "psp",
         target_os = "xous",
         target_os = "solid_asp3",
-        all(target_family = "unix", not(target_os = "espidf"), not(target_os = "l4re"), not(target_os = "rtems"), not(target_os = "nuttx")),
+        all(target_family = "unix", not(target_os = "espidf"), not(target_os = "l4re"), not(target_os = "nuttx")),
         all(target_vendor = "fortanix", target_env = "sgx"),
     ))] {
         mod gcc;

library/unwind/src/lib.rs

@@ -20,7 +20,6 @@ cfg_if::cfg_if! {
         target_os = "l4re",
         target_os = "none",
         target_os = "espidf",
-        target_os = "rtems",
         target_os = "nuttx",
     ))] {
         // These "unix" family members do not have unwinder.