Fix <rdar://problem/23719432> [practicalswift] Compiler crashes on &(Int:_)

We were using the wrong conversion from lvalue to rvalue, which wasn't digging
into tuple lvalues.

Author: lattner

lib/Sema/CSApply.cpp

@@ -2651,11 +2651,10 @@ namespace {
       // case (when we turn the inout into an UnsafePointer) than to try to
       // discover that we're in that case right now.
       expr->getSubExpr()->propagateLValueAccessKind(AccessKind::ReadWrite);
-      auto lvTy = expr->getSubExpr()->getType()->castTo<LValueType>();
+      auto objectTy = expr->getSubExpr()->getType()->getRValueType();
 
-      // The type is simply inout.
-      // Compute the type of the inout expression.
-      expr->setType(InOutType::get(lvTy->getObjectType()));
+      // The type is simply inout of whatever the lvalue's object type was.
+      expr->setType(InOutType::get(objectTy));
       return expr;
     }
 

test/Parse/recovery.swift

@@ -699,3 +699,10 @@ func test23086402(a: A23086402) {
   print(a.b.c + "")  // expected-error {{cannot convert value of type '[String]' to expected argument type 'String'}}
 }
 
+// <rdar://problem/23719432> [practicalswift] Compiler crashes on &(Int:_)
+func test23719432() {
+  var x = 42
+  &(Int:x)  // expected-error {{'&' can only appear immediately in a call argument list}}
+}
+
+