Fix helper header when using c++17 (#1666)

This will fix issue #1621. It also adds tests for is_callable with c++11, c++14, and c++17.

The fallback implementation was completely broken so I rewrote it so it pass the tests as well. This should be used instead of PR #1631.

tests/src/cppstd/hipInvocable11Fallback.cpp

@@ -0,0 +1,34 @@
+/*
+Copyright (c) 2019 - present Advanced Micro Devices, Inc. All rights reserved.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+/* HIT_START
+ * BUILD: %t %s ../test_common.cpp HIPCC_OPTIONS -std=c++11 EXCLUDE_HIP_PLATFORM nvcc
+ * TEST: %t
+ * HIT_END
+ */
+
+// Ensure fallback path is chosen
+#define HIP_HAS_RESULT_OF_SFINAE 0
+#define HIP_HAS_INVOCABLE 0
+#include "is_callable_test.hpp"
+#include <test_common.h>
+
+int main() { passed(); }