add assembly test for rust-lang#83585

Author: tesuji

tests/assembly/issue-83585-small-pod-struct-equality.rs

@@ -0,0 +1,30 @@
+//@ assembly-output: emit-asm
+//@ compile-flags:-Copt-level=3
+//@ only-x86_64
+
+#![crate_type = "lib"]
+
+#[no_mangle]
+type T = u8;
+type T1 = (T, T, T, T, T, T, T, T);
+type T2 = [T; 8];
+
+#[no_mangle]
+// CHECK-LABEL: foo1a
+// CHECK: cmp
+// CHECK-NEXT: set
+// CHECK-NEXT: ret
+pub fn foo1a(a: T1, b: T1) -> bool {
+    a == b
+}
+
+#[no_mangle]
+// CHECK-LABEL: foo1b
+// CHECK: mov
+// CHECK-NEXT: cmp
+// CHECK-NEXT: set
+// CHECK-NEXT: ret
+pub fn foo1b(a: &T1, b: &T1) -> bool {
+    a == b
+}
+