Add Verifier Tests for A Tricky Typealias Miscompile

Author: CodaFi

test/Incremental/Verifier/multi-file-private/Inputs/Inner.swift

@@ -0,0 +1,14 @@
+// expected-provides{{Inner}}
+// expected-private-member{{main.Inner.init}}
+public struct Inner {}
+
+// expected-provides{{Foo}}
+public typealias Foo = () -> (Inner)
+
+// expected-provides{{blah}}
+public func blah(foo: Foo) {}
+
+// expected-provides{{defaultFoo}}
+public var defaultFoo: Foo = {
+  return Inner()
+}

test/Incremental/Verifier/multi-file-private/Inputs/UsesInner.swift

@@ -0,0 +1,8 @@
+// expected-provides{{Inner}}
+// expected-provides{{defaultFoo}}
+// expected-provides{{blah}}
+// expected-provides{{Foo}}
+// expected-provides{{??}}
+public func blah(foo: Foo?) {
+  blah(foo: foo ?? defaultFoo)
+}

test/Incremental/Verifier/multi-file/Inputs/Inner.swift

@@ -0,0 +1,14 @@
+// expected-provides{{Inner}}
+// expected-cascading-member{{main.Inner.init}}
+public struct Inner {}
+
+// expected-provides{{Foo}}
+public typealias Foo = () -> (Inner)
+
+// expected-provides{{blah}}
+public func blah(foo: Foo) {}
+
+// expected-provides{{defaultFoo}}
+public var defaultFoo: Foo = {
+  return Inner()
+}

test/Incremental/Verifier/multi-file/Inputs/UsesInner.swift

@@ -0,0 +1,14 @@
+// FIXME: This dependency ONLY occurs with private dependencies. Otherwise we
+// rely on the interface hash changing to cause this file to be rebuilt, which
+// will *not* work with type fingerprints enabled.
+// See rdar://63984581
+// fixme-expected-provides{{Inner}}
+
+// expected-provides{{defaultFoo}}
+// expected-provides{{blah}}
+// expected-provides{{Optional}}
+// expected-provides{{Foo}}
+// expected-provides{{??}}
+public func blah(foo: Optional<Foo>) {
+  blah(foo: foo ?? defaultFoo)
+}