[test] Add a couple of test cases

test/Constraints/array_literal.swift

@@ -355,3 +355,10 @@ func testSR8385() {
   let _: [SR8385] = ["hello", SR8385.text("world")]
   let _: [SR8385] = ["hello", .text("world")]
 }
+
+struct TestMultipleOverloadedInits {
+  var x: Double
+  func foo() {
+    let _ = [Float(x), Float(x), Float(x), Float(x)]
+  }
+}

test/Constraints/iuo.swift

@@ -229,3 +229,12 @@ let _: Int = r
 // SR-11998 / rdar://problem/58455441
 class C<T> {}
 var sub: C! = C<Int>()
+
+// FIXME: We probably shouldn't support this, we don't support other
+// 'direct call' features such as default arguments for curried calls.
+struct CurriedIUO {
+  func silly() -> Int! { nil }
+  func testSilly() {
+    let _: Int = CurriedIUO.silly(self)()
+  }
+}

test/Constraints/tuple_arguments.swift

@@ -1768,3 +1768,12 @@ func noescapeSplat() {
   }
 }
 
+func variadicSplat() {
+  func takesFnWithVarg(fn: (Int, Int...) -> Void) {}
+  takesFnWithVarg { x in // expected-error {{contextual closure type '(Int, Int...) -> Void' expects 2 arguments, but 1 was used in closure body}}
+    _ = x.1.count
+  }
+  takesFnWithVarg { x, y in
+    _ = y.count
+  }
+}

test/Index/index_keypath_member_lookup.swift

@@ -158,3 +158,11 @@ extension Foo {
     // CHECK: [[@LINE-1]]:5 | instance-property/Swift | prop | [[PROP_USR]] | Ref,Read,RelCont | rel: 1
   }
 }
+
+// Also make sure we don't crash for multiple overloads.
+@dynamicMemberLookup
+protocol P {}
+extension P {
+  subscript<T>(dynamicMember keyPath: KeyPath<Bar, T>) -> Int { 0 }
+  subscript<T>(dynamicMember keyPath: KeyPath<P, T>) -> Int { 0 }
+}