[test] TBD: add a tbd gen test for generating linker directives

Author: nkcsgexi

test/TBD/linker-directives.swift

@@ -0,0 +1,17 @@
+// REQUIRES: VENDOR=apple 
+// RUN: %empty-directory(%t)
+
+// RUN: %target-swift-frontend -typecheck %s -tbd-is-installapi -emit-tbd -emit-tbd-path %t/linker_directives.tbd
+// RUN: %FileCheck %s --check-prefix CHECK-HAS --check-prefix CHECK-HAS-NOT < %t/linker_directives.tbd
+// RUN: %target-swift-frontend -typecheck %s -emit-tbd -emit-tbd-path %t/linker_directives.tbd
+// RUN: %FileCheck %s --check-prefix CHECK-HAS --check-prefix CHECK-HAS-NOT < %t/linker_directives.tbd
+
+@available(OSX 10.8, *)
+@_originallyDefinedIn(module: "ToasterKit", macOS 10.15)
+public func toast() {}
+
+// CHECK-HAS: $ld$hide$os10.14$_$s10ToasterKit5toastyyF
+// CHECK-HAS: $ld$hide$os10.8$_$s10ToasterKit5toastyyF
+
+// CHECK-HAS-NOT-NOT: $ld$hide$os10.15$_$s10ToasterKit5toastyyF
+// CHECK-HAS-NOT-NOT: $ld$hide$os10.7$_$s10ToasterKit5toastyyF