[test] Add a cross-module struct initializer test with private fields

Author: jrose-apple

test/SILOptimizer/Inputs/definite_init_cross_module/OtherModule.swift

@@ -24,3 +24,12 @@ public struct GenericPoint<T> {
     self.y = y
   }
 }
+
+public struct PrivatePoint {
+  private var x, y: Double
+
+  public init(x: Double, y: Double) {
+    self.x = x
+    self.y = y
+  }
+}

test/SILOptimizer/definite_init_cross_module.swift

@@ -181,3 +181,19 @@ extension NonnullWrapper {
     // zeroing initializer.
   } // expected-error {{'self.init' isn't called on all paths before returning from initializer}}
 }
+
+
+extension PrivatePoint {
+  init(xxx: Double, yyy: Double) {
+    // This is OK
+    self.init(x: xxx, y: yyy)
+  }
+
+  init(other: PrivatePoint) {
+    // This is OK
+    self = other
+  }
+
+  init() {
+  } // expected-error {{'self.init' isn't called on all paths before returning from initializer}}
+}

test/SILOptimizer/definite_init_cross_module_swift4.swift

@@ -1,6 +1,6 @@
 // RUN: %empty-directory(%t)
 // RUN: %target-swift-frontend -emit-module -emit-module-path=%t/OtherModule.swiftmodule %S/Inputs/definite_init_cross_module/OtherModule.swift
-// RUN: %target-swift-frontend -emit-sil -verify -I %t -swift-version 4 %s > /dev/null -import-objc-header %S/Inputs/definite_init_cross_module/BridgingHeader.h
+// RUN: %target-swift-frontend -emit-sil -verify -verify-ignore-unknown -I %t -swift-version 4 %s > /dev/null -import-objc-header %S/Inputs/definite_init_cross_module/BridgingHeader.h
 
 import OtherModule
 
@@ -221,3 +221,21 @@ extension NonnullWrapper {
     // zeroing initializer.
   }
 }
+
+
+extension PrivatePoint {
+  init(xxx: Double, yyy: Double) {
+    // This is OK
+    self.init(x: xxx, y: yyy)
+  }
+
+  init(other: PrivatePoint) {
+    // This is OK
+    self = other
+  }
+
+  // Ideally we wouldn't mention the names of non-public stored properties
+  // across module boundaries, but this will go away in Swift 5 mode anyway.
+  init() {
+  } // expected-error {{return from initializer without initializing all stored properties}}
+}