Add test for building a module with -use-interface-for-module that imports a module with package name

Ref: rdar://108945440

Author: elsh

test/api-digester/use-interface-for-module-with-package-name.swift

@@ -0,0 +1,56 @@
+// REQUIRES: VENDOR=apple
+
+// RUN: %empty-directory(%t.mod)
+// RUN: %empty-directory(%t.sdk)
+// RUN: %empty-directory(%t.module-cache)
+// RUN: split-file %s %t
+
+// Make sure api-digester loads an interface with package-name correctly
+
+// Generate module Lib
+// RUN: %target-swift-frontend  %t/Lib.swift -emit-module -module-name Lib -emit-module-path %t.mod/Lib.swiftmodule -emit-module-interface-path %t.mod/Lib.swiftinterface -emit-private-module-interface-path %t.mod/Lib.private.swiftinterface -package-name myLib -parse-as-library -enable-library-evolution -module-cache-path %t.module-cache -swift-version 5
+
+// Dumping sdk for Lib ABI via .swiftmodule file should work
+// RUN: %api-digester -dump-sdk -abort-on-module-fail -abi -module Lib -o - -module-cache-path %t.module-cache -I %t.mod > %t.dump-lib-interface.json
+
+// Dumping sdk file for Lib ABI via .swiftinterface file should work
+// RUN: %api-digester -dump-sdk -abort-on-module-fail -abi -module Lib -use-interface-for-module Lib -o - -module-cache-path %t.module-cache -I %t.mod > %t.dump-lib-interface.json
+
+// Generate module Client
+// RUN: %target-swift-frontend %t/Client.swift -emit-module -module-name Client -emit-module-path %t.mod/Client.swiftmodule -emit-module-interface-path %t.mod/Client.swiftinterface -emit-private-module-interface-path %t.mod/Client.private.swiftinterface -package-name myLib -parse-as-library -enable-library-evolution -module-cache-path %t.module-cache -swift-version 5  -I %t.mod
+
+// RUN: rm -f %t.mod/Lib.swiftmodule
+// RUN: rm -f %t.module-cache/Lib*.swiftmodule
+
+// Dumping sdk for Client ABI via .swiftmodule file should work
+// RUN: %api-digester -dump-sdk -abort-on-module-fail -abi -module Client -o - -module-cache-path %t.module-cache -I %t.mod > %t.dump-client-interface.json
+
+// Dumping sdk for Client ABI via .swiftinterface file should work
+// RUN: %api-digester -dump-sdk -abort-on-module-fail -abi -module Client -use-interface-for-module Client -o - -module-cache-path %t.module-cache -I %t.mod > %t.dump-client-interface.json
+
+
+//--- Lib.swift
+package class P {
+  package class func foo() {}
+  package func foo2(_ : Int) {}
+  package weak var bar : P?
+  package var bar2 : P?
+}
+
+package func lambdafunc() -> (P) -> () { return { _ in } }
+
+public struct S {
+  package init(_ : P?) {}
+  public static func baz(_ arg: String?) {}
+}
+
+//--- Client.swift
+import Lib
+
+func clientFunc() {
+  let s = S(nil)
+  S.baz("")
+  P.foo()
+  let result = lambdafunc()
+  print(s, result)
+}