[di] Show the swift code necessary to generate some of the derived self cases.

This will make it easier to understand how these test cases come up in the wild.

rdar://31880847

Author: gottesmm

test/SILOptimizer/definite_init_markuninitialized_derivedself.sil

@@ -40,6 +40,26 @@ sil @getSomeOptionalClass : $@convention(thin) () -> Optional<SomeClass>
 // Tests //
 ///////////
 
+// This can be generated by using:
+//
+// func makesInt() -> Int { return 0 }
+// func takesIntInout(i: inout Int) -> () {}
+// 
+// class RootClassWithIVars {
+//   var x: Int
+//   var y: Int
+//   var z: (Int, Int)
+//   init() {
+//   }
+// }
+// 
+// class DerivedClassWithIVars : RootClassWithIVars {
+//   var a: Int
+//   override init() {
+//     a = makesInt()
+//   }
+// }
+//
 sil @derived_test1 :  $@convention(method) (@owned DerivedClassWithIVars) -> @owned DerivedClassWithIVars {
 bb0(%0 : $DerivedClassWithIVars):
   %1 = alloc_box $<τ_0_0> { var τ_0_0 } <DerivedClassWithIVars>
@@ -70,6 +90,24 @@ bb0(%0 : $DerivedClassWithIVars):
   return %18 : $DerivedClassWithIVars
 }
 
+// This is testing the following swift:
+//
+// func makesInt() -> Int { return 0 }
+// func takesIntInout(i: inout Int) -> () {}
+// 
+// class RootClassWithIVars {
+//   var x: Int
+//   var y: Int
+//   var z: (Int, Int)
+//   init() {
+//   }
+// }
+// 
+// class DerivedClassWithIVars : RootClassWithIVars {
+//   var a: Int
+//   override init() {
+//   }
+// }
 sil @derived_test2 :  $@convention(method) (@owned DerivedClassWithIVars) -> @owned DerivedClassWithIVars {
 bb0(%0 : $DerivedClassWithIVars):
   %1 = alloc_box $<τ_0_0> { var τ_0_0 } <DerivedClassWithIVars>
@@ -167,6 +205,21 @@ bb0(%0 : $DerivedClassWithNontrivialStoredProperties):
 }
 
 // <rdar://problem/18199087> DI doesn't catch use of super properties lexically inside super.init call
+//
+// To recreate this:
+//
+// class Foo {
+//   var x: Int
+//   init() {}
+//   init(i: Int) {}
+// }
+// 
+// class Foo2 : Foo {
+//   override init() {    
+//     super.init(i: self.x) // <--- The important part.
+//   }
+// }
+//
 sil @super_init_out_of_order :  $@convention(method) (@owned DerivedClassWithIVars, Int) -> @owned DerivedClassWithIVars {
 bb0(%0 : $DerivedClassWithIVars, %i : $Int):
   %1 = alloc_box $<τ_0_0> { var τ_0_0 } <DerivedClassWithIVars>