Fix cortex-m-semihosting inline-asm on nightly

Author: adamgreig

cortex-m-semihosting/src/lib.rs

@@ -213,7 +213,12 @@ pub unsafe fn syscall1(_nr: usize, _arg: usize) -> usize {
         #[cfg(all(thumb, feature = "inline-asm", not(feature = "no-semihosting")))]
         () => {
             let mut nr = _nr;
-            llvm_asm!("bkpt 0xAB" : "+{r0}"(nr) : "{r1}"(_arg) :: "volatile");
+            core::arch::asm!(
+                "bkpt #0xab",
+                inout("r0") nr,
+                in("r1") arg,
+                options(nomem, nostack, preserves_flags)
+            );
             nr
         }