[AST] Strip InOutType when cloning a parameter.

Fixes rdar://problem/34789779, where initializer inheritance was breaking
in the presence of 'inout' parameters.

Author: DougGregor

lib/AST/Decl.cpp

@@ -4202,7 +4202,9 @@ ParamDecl::ParamDecl(Specifier specifier,
 ParamDecl::ParamDecl(ParamDecl *PD, bool withTypes)
   : VarDecl(DeclKind::Param, /*IsStatic*/false, PD->getSpecifier(),
             /*IsCaptureList*/false, PD->getNameLoc(), PD->getName(),
-            PD->hasType() && withTypes? PD->getType() : Type(),
+            PD->hasType() && withTypes
+              ? PD->getType()->getInOutObjectType()
+              : Type(),
             PD->getDeclContext()),
     ArgumentName(PD->getArgumentName()),
     ArgumentNameLoc(PD->getArgumentNameLoc()),
@@ -4215,7 +4217,7 @@ ParamDecl::ParamDecl(ParamDecl *PD, bool withTypes)
     typeLoc.setType(Type());
 
   if (withTypes && PD->hasInterfaceType())
-    setInterfaceType(PD->getInterfaceType());
+    setInterfaceType(PD->getInterfaceType()->getInOutObjectType());
 }
 
 

test/decl/inherit/initializer.swift

@@ -150,3 +150,34 @@ func testClassInGenericFunc<T>(t: T) {
 
   _ = B(t: t)
 }
+
+// rdar://problem/34789779
+public class Node {
+  var data : Data
+
+  public struct Data {
+    var index: Int32 = 0// for helpers
+  }
+
+ init(data: inout Data/*, context: Context*/) {
+   self.data = data
+ }
+
+ public required init(node: Node) {
+   data = node.data
+ }
+}
+
+final class SubNode : Node {
+  var a: Int
+
+  required init(node: Node) {
+    a = 1
+    super.init(node: node)
+  }
+
+  init(data: inout Data, additionalParam: Int) {
+    a = additionalParam
+    super.init(data: &data)
+  }
+}