[ReconstructType] Fix decl lookup when there are multiple constructors

We were failing to find init() decls whenever there was more than one
candidate.

The mangled function type we get will be (args...) -> T, but the real
thing is (T.Type) -> (args...) -> T. Strip the metatype so we can match
successfully.

Author: benlangmuir

lib/IDE/ReconstructType.cpp

@@ -1058,6 +1058,15 @@ static void VisitNodeConstructor(
           case TypeKind::Function: {
             const AnyFunctionType *identifier_func =
                 identifier_type->getAs<AnyFunctionType>();
+
+            // inits are typed as (Foo.Type) -> (args...) -> Foo, but don't
+            // assert that in case we're dealing with broken code.
+            if (identifier_func->getInput()->is<AnyMetatypeType>() &&
+                identifier_func->getResult()->is<AnyFunctionType>()) {
+              identifier_func =
+                  identifier_func->getResult()->getAs<AnyFunctionType>();
+            }
+
             const AnyFunctionType *type_func =
                 type_result._types.front()->getAs<AnyFunctionType>();
             if (CanType(identifier_func->getResult()

test/IDE/reconstruct_type_from_mangled_name.swift

@@ -7,6 +7,15 @@ struct Mystruct1 {
   var intField = 3
 // CHECK: decl: var intField: Int
 }
+struct MyStruct2 {
+// CHECK: decl: struct MyStruct2
+  init() {}
+// CHECK: decl: init()
+  init(x: Int) {}
+// CHECK: decl: init(x: Int)
+  init(x: Int, y: Int) {}
+// CHECK: decl: init(x: Int, y: Int)
+}
 
 class Myclass1 {
 // CHECK: decl: class Myclass1
@@ -16,13 +25,14 @@ class Myclass1 {
 
 func f1() {
 // CHECK: decl: func f1()
-  var s1ins = Mystruct1()
+  var s1ins = Mystruct1() // Implicit ctor
 // CHECK: decl: var s1ins: Mystruct1
-// FIXME: missing init()?
-// CHECK: dref: FAILURE	for 'Mystruct1' usr=s:FV14swift_ide_test9Mystruct1cFT_S0_
-// CHECK: type: Mystruct1
+// CHECK: dref: init() for 'Mystruct1'
+  _ = Mystruct1(intField: 1) // Implicit ctor
+// CHECK: dref: init(intField: Int)	for 'Mystruct1'
 
   s1ins.intField = 34
+// CHECK: type: Mystruct1
 // CHECK: type: Int
 
   var c1ins = Myclass1()
@@ -70,6 +80,9 @@ class Myclass2 {
 
     arr3.append(Myclass1())
 // CHECK: type: @lvalue Array<Myclass1> -> Myclass1 -> ()
+
+    _ = Myclass2.init()
+// CHECK: dref: init()
   }
 }