redox-rt: clean up unused code

Removes unused imports, and replaces calls to `core::intrinsics::abort`
with `panic` macro call.

redox-rt/src/lib.rs

@@ -1,16 +1,9 @@
 #![no_std]
-#![feature(
-    asm_const,
-    core_intrinsics,
-    int_roundings,
-    let_chains,
-    slice_ptr_get,
-    sync_unsafe_cell
-)]
+#![feature(int_roundings, let_chains, slice_ptr_get, sync_unsafe_cell)]
 #![forbid(unreachable_patterns)]
 
 use core::{
-    cell::{SyncUnsafeCell, UnsafeCell},
+    cell::UnsafeCell,
     mem::{size_of, MaybeUninit},
 };
 
@@ -232,14 +225,14 @@ pub(crate) struct StaticProcInfo {
     proc_fd: MaybeUninit<FdGuard>,
     has_proc_fd: bool,
 }
-struct DynamicProcInfo {
-    pgid: u32,
-    euid: u32,
-    suid: u32,
-    ruid: u32,
-    egid: u32,
-    rgid: u32,
-    sgid: u32,
+pub struct DynamicProcInfo {
+    pub pgid: u32,
+    pub euid: u32,
+    pub suid: u32,
+    pub ruid: u32,
+    pub egid: u32,
+    pub rgid: u32,
+    pub sgid: u32,
 }
 
 static DYNAMIC_PROC_INFO: Mutex<DynamicProcInfo> = Mutex::new(DynamicProcInfo {

redox-rt/src/signal.rs

@@ -172,7 +172,7 @@ unsafe fn inner(stack: &mut SigStack) {
                 CallFlags::empty(),
                 &[ProcCall::Exit as u64, u64::from(sig) << 8],
             );
-            core::intrinsics::abort()
+            panic!()
         }
         SigactionKind::Handled { handler } => handler,
     };

redox-rt/src/sys.rs

@@ -324,7 +324,7 @@ pub fn posix_exit(status: i32) -> ! {
     )
     .expect("failed to call proc mgr with Exit");
     let _ = syscall::write(1, b"redox-rt: ProcCall::Exit FAILED, abort()ing!\n");
-    core::intrinsics::abort();
+    panic!();
 }
 pub fn setrens(rns: usize, ens: usize) -> Result<()> {
     this_proc_call(