[Test] Add typechecker test cases for unresolved member expr

Some uncommon cases including:
* Closure static properties
* Nested types

Author: rintaro

test/expr/delayed-ident/nested_type.swift

@@ -0,0 +1,27 @@
+// RUN: %target-typecheck-verify-swift
+
+// Nested subclass, typealias Self.
+class Base {
+  class Derived : Base {
+    init(x: Int) {}
+  }
+  typealias Ident = Base
+}
+
+let _: Base = .Derived(x: 12)
+let _: Base = .Ident()
+
+// Typealias in protocol.
+protocol P {
+  typealias Impl1 = ConcreteP
+}
+extension P {
+  typealias Impl2 = ConcreteP
+}
+struct ConcreteP : P {
+}
+
+let _: P = .Impl1()
+let _: P = .Impl2()
+let _: ConcreteP = .Impl1()
+let _: ConcreteP = .Impl2()

test/expr/delayed-ident/static_var.swift

@@ -35,3 +35,16 @@ struct Foo {
 func & (x: Foo, y: Foo) -> Foo { }
 
 var fooValue: Foo = .Bar & .Wibble
+
+// Static closure variables.
+struct HasClosure {
+  static var factoryNormal: (Int) -> HasClosure = { _ in .init() }
+  static var factoryReturnOpt: (Int) -> HasClosure? = { _ in .init() }
+  static var factoryIUO: ((Int) -> HasClosure)! = { _ in .init() }
+  static var factoryOpt: ((Int) -> HasClosure)? = { _ in .init() }
+}
+var _: HasClosure = .factoryNormal(0)
+var _: HasClosure = .factoryReturnOpt(1)!
+var _: HasClosure = .factoryIUO(2)
+var _: HasClosure = .factoryOpt(3) // expected-error {{static property 'factoryOpt' is not a function}}
+var _: HasClosure = .factoryOpt!(4) // expected-error {{type of expression is ambiguous without more context}}