Add mir-opt test for asm_unwind + panic=abort

Author: luqmana

src/test/mir-opt/asm_unwind_panic_abort.main.AbortUnwindingCalls.after.mir

@@ -0,0 +1,24 @@
+// MIR for `main` after AbortUnwindingCalls
+
+fn main() -> () {
+    let mut _0: ();                      // return place in scope 0 at $DIR/asm_unwind_panic_abort.rs:11:11: 11:11
+    let _1: ();                          // in scope 0 at $DIR/asm_unwind_panic_abort.rs:13:9: 13:49
+    scope 1 {
+    }
+
+    bb0: {
+        StorageLive(_1);                 // scope 1 at $DIR/asm_unwind_panic_abort.rs:13:9: 13:49
+        _1 = const ();                   // scope 1 at $DIR/asm_unwind_panic_abort.rs:13:9: 13:49
+        asm!("", options(MAY_UNWIND)) -> [return: bb1, unwind: bb2]; // scope 1 at $DIR/asm_unwind_panic_abort.rs:13:9: 13:49
+    }
+
+    bb1: {
+        StorageDead(_1);                 // scope 1 at $DIR/asm_unwind_panic_abort.rs:13:48: 13:49
+        _0 = const ();                   // scope 1 at $DIR/asm_unwind_panic_abort.rs:12:5: 14:6
+        return;                          // scope 0 at $DIR/asm_unwind_panic_abort.rs:15:2: 15:2
+    }
+
+    bb2 (cleanup): {
+        abort;                           // scope 0 at $DIR/asm_unwind_panic_abort.rs:11:1: 15:2
+    }
+}

src/test/mir-opt/asm_unwind_panic_abort.rs

@@ -0,0 +1,15 @@
+//! Tests that unwinding from an asm block is caught and forced to abort
+//! when `-C panic=abort`.
+
+// min-llvm-version: 13.0.0
+// compile-flags: -C panic=abort
+// no-prefer-dynamic
+
+#![feature(asm_unwind)]
+
+// EMIT_MIR asm_unwind_panic_abort.main.AbortUnwindingCalls.after.mir
+fn main() {
+    unsafe {
+        std::arch::asm!("", options(may_unwind));
+    }
+}