fix Issue 9537 - auto ref returns a reference its own stack

test/fail_compilation/fail9537.d

@@ -0,0 +1,27 @@
+/*
+TEST_OUTPUT:
+---
+fail_compilation/fail9537.d(26): Error: foo(tuple(1, 2)) is not an lvalue
+---
+*/
+
+struct Tuple(T...)
+{
+    T field;
+    alias field this;
+}
+
+Tuple!T tuple(T...)(T args)
+{
+    return Tuple!T(args);
+}
+
+auto ref foo(T)(auto ref T t)
+{
+    return t[0];    // t[0] is deduced to non-ref
+}
+
+void main()
+{
+    int* p = &foo(tuple(1, 2));
+}