Include the panic_unwind feature and specify the unwind crate unconditionally and remove the libc crate.

Author: xingxue-ibm

tests/ui/extern-flag/auxiliary/panic_handler.rs

@@ -1,20 +1,9 @@
-#![feature(lang_items)]
+#![feature(lang_items, panic_unwind)]
 #![no_std]
-#![cfg_attr(target_os = "aix", feature(panic_unwind))]
 
-// Since `rustc` generally passes `-nodefaultlibs` to the linker,
-// Rust programs link necessary system libraries via `#[link()]`
-// attributes in the `libc` crate. `libc` is a dependency of `std`,
-// but as we are `#![no_std]`, we need to include it manually.
-// Except on windows-msvc.
-#![feature(rustc_private)]
-#[cfg(not(all(windows, target_env = "msvc")))]
-extern crate libc;
-
-// Since crate `unwind` is a dependency of crate `std`, and we are using
-// `#![no_std]`, `libunwind` is not included in the link command on AIX
-// by default. We need to include crate `unwind` manually.
-#[cfg(target_os = "aix")]
+// Since the `unwind` crate is a dependency of the `std` crate, and we have
+// `#![no_std]`, the unwinder is not included in the link command by default.
+// We need to include crate `unwind` manually.
 extern crate unwind;
 
 #[panic_handler]

tests/ui/runtime/signal-alternate-stack-cleanup.rs

@@ -29,7 +29,10 @@ fn main() {
         // Install signal handler that runs on alternate signal stack.
         let mut action: sigaction = std::mem::zeroed();
         action.sa_flags = (SA_ONSTACK | SA_SIGINFO) as _;
-        action.sa_sigaction = signal_handler as sighandler_t;
+        #[cfg(not(target_os = "aix"))]
+        { action.sa_sigaction = signal_handler as sighandler_t}
+        #[cfg(target_os = "aix")]
+        { action.sa_union.__su_sigaction = signal_handler as sighandler_t }
         sigaction(SIGWINCH, &action, std::ptr::null_mut());
 
         // Send SIGWINCH on exit.