test: add a linker directive test for ios

Author: nkcsgexi

test/IRGen/original-defined-attr-linker-hide-ios.swift

@@ -0,0 +1,16 @@
+// RUN: %target-swift-frontend -swift-version 4 -enforce-exclusivity=checked %s -emit-ir -module-name CurrentModule -D CURRENT_MODULE | %FileCheck %s
+
+// REQUIRES: OS=ios
+
+@available(iOS 5.0, OSX 10.10, *)
+@_originallyDefinedIn(module: "OriginalModule", iOS 5.4, OSX 10.13)
+public struct Entity {
+  public func addEntity(_ e: Entity) {}
+  public func removeEntity(_ e: Entity) {}
+}
+
+// CHECK: $ld$hide$os5.0$_$s14OriginalModule6EntityVN
+// CHECK: $ld$hide$os5.1$_$s14OriginalModule6EntityVN
+// CHECK: $ld$hide$os5.2$_$s14OriginalModule6EntityVN
+// CHECK: $ld$hide$os5.3$_$s14OriginalModule6EntityVN
+// CHECK-NOT: $ld$hide$os5.4$_$s14OriginalModule6EntityVN