AArch64: map bare-metal arm64-macho triple to MachO MC layer.

Far better than an assertion about expecting ELF.

llvm-svn: 239647
diff --git a/llvm/test/CodeGen/AArch64/simple-macho.ll b/llvm/test/CodeGen/AArch64/simple-macho.ll
new file mode 100644
index 0000000..e9dd98e
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/simple-macho.ll
@@ -0,0 +1,12 @@
+; RUN: llc -mtriple=arm64-macho -o - %s | FileCheck %s
+; RUN: llc -mtriple=arm64-macho -filetype=obj -o %t %s
+; RUN: llvm-objdump -triple=arm64-macho -d %t | FileCheck --check-prefix=CHECK-OBJ %s
+
+define void @foo() {
+; CHECK-LABEL: _foo:
+; CHECK: ret
+
+; CHECK-OBJ: 0: c0 03 5f d6 ret
+
+  ret void
+}
\ No newline at end of file