add addtl coverage for when the moveonly type is not used

We want to ensure that the deserialization error added
for this test doesn't trigger when the moveonly type
is not used by the importing module.

part of rdar://106262652

Author: kavon

test/Serialization/Inputs/moveonly_deinit.swift

@@ -17,3 +17,11 @@ public enum MoveOnlyEnum {
 
     deinit { }
 }
+
+public struct NormalStruct {
+  private let desc: Int
+
+  public init(desc: Int) {
+    self.desc = desc
+  }
+}

test/Serialization/moveonly_error_on_import_into_module_without_flag.swift

@@ -1,7 +1,8 @@
 // RUN: %empty-directory(%t)
 // TODO: re-enable the simplification passes once rdar://104875010 is fixed
 // RUN: %target-swift-frontend -Xllvm -sil-disable-pass=simplification -emit-module -o %t/Library.swiftmodule -module-name Library %S/Inputs/moveonly_deinit.swift -enable-experimental-move-only
-// RUN: not %target-swift-frontend -I %t %s -emit-sil -o /dev/null 2>&1 | %FileCheck %s
+// RUN: not %target-swift-frontend -DUSE_MOVEONLY_TYPE -I %t %s -emit-sil -o /dev/null 2>&1 | %FileCheck %s
+// RUN: %target-swift-frontend -I %t %s -emit-sil -verify -o /dev/null
 
 // This test makes sure that if we import a move only type and do not set the
 // experimental move only flag, we get a nice error.
@@ -10,5 +11,8 @@ import Library
 
 // CHECK: error: Can not import module 'Library' that uses move only features when experimental move only is disabled! Pass the frontend flag -enable-experimental-move-only to swift to enable the usage of this language feature
 
-func f(_ k: MoveOnlyStruct) {
-}
+#if USE_MOVEONLY_TYPE
+func f(_ k: MoveOnlyStruct) {}
+#endif
+
+func g(_ k: NormalStruct) {}