simplify no-std tests

set panic=abort so that we do not need this eh_personality thing

src/tools/miri/tests/fail/alloc/no_global_allocator.rs

@@ -1,7 +1,8 @@
+//@compile-flags: -Cpanic=abort
 //@normalize-stderr-test: "OS `.*`" -> "$$OS"
 // Make sure we pretend the allocation symbols don't exist when there is no allocator
 
-#![feature(lang_items, start)]
+#![feature(start)]
 #![no_std]
 
 extern "Rust" {
@@ -21,6 +22,3 @@ fn start(_: isize, _: *const *const u8) -> isize {
 fn panic_handler(_: &core::panic::PanicInfo) -> ! {
     loop {}
 }
-
-#[lang = "eh_personality"]
-fn eh_personality() {}

src/tools/miri/tests/fail/panic/no_std.rs

@@ -1,5 +1,6 @@
-#![feature(lang_items, start, core_intrinsics)]
+#![feature(start, core_intrinsics)]
 #![no_std]
+//@compile-flags: -Cpanic=abort
 // windows tls dtors go through libstd right now, thus this test
 // cannot pass. When windows tls dtors go through the special magic
 // windows linker section, we can run this test on windows again.
@@ -36,6 +37,3 @@ fn panic_handler(panic_info: &core::panic::PanicInfo) -> ! {
     writeln!(HostErr, "{panic_info}").ok();
     core::intrinsics::abort(); //~ ERROR: the program aborted execution
 }
-
-#[lang = "eh_personality"]
-fn eh_personality() {}

src/tools/miri/tests/pass/miri-alloc.rs

@@ -1,5 +1,6 @@
-#![feature(lang_items, start)]
+#![feature(start)]
 #![no_std]
+//@compile-flags: -Cpanic=abort
 // windows tls dtors go through libstd right now, thus this test
 // cannot pass. When windows tls dtors go through the special magic
 // windows linker section, we can run this test on windows again.
@@ -24,6 +25,3 @@ fn start(_: isize, _: *const *const u8) -> isize {
 fn panic_handler(_: &core::panic::PanicInfo) -> ! {
     loop {}
 }
-
-#[lang = "eh_personality"]
-fn eh_personality() {}

src/tools/miri/tests/pass/no_std.rs

@@ -1,4 +1,5 @@
-#![feature(lang_items, start)]
+//@compile-flags: -Cpanic=abort
+#![feature(start)]
 #![no_std]
 
 // Plumbing to let us use `writeln!` to host stdout:
@@ -32,6 +33,3 @@ fn start(_: isize, _: *const *const u8) -> isize {
 fn panic_handler(_: &core::panic::PanicInfo) -> ! {
     loop {}
 }
-
-#[lang = "eh_personality"]
-fn eh_personality() {}

src/tools/miri/tests/pass/overloaded-calls-simple.rs

@@ -1,4 +1,4 @@
-#![feature(lang_items, unboxed_closures, fn_traits)]
+#![feature(unboxed_closures, fn_traits)]
 
 struct S3 {
     x: i32,