Add missing include

type_traits in vulkan_enums.hpp for underlying_type usage

Bug: b/424075772
Change-Id: I24816048b69184932e40c836ae08775ad0e1edd3
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/75728
Tested-by: Shahbaz Youssefi <syoussefi@google.com>
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Presubmit-Ready: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Shahbaz Youssefi <syoussefi@google.com>
Reviewed-by: Shahbaz Youssefi <syoussefi@google.com>

include/vulkan/vulkan_enums.hpp

diff --git a/include/vulkan/vulkan_enums.hpp b/include/vulkan/vulkan_enums.hpp
index 977f648..5f5d896 100644
--- a/include/vulkan/vulkan_enums.hpp
+++ b/include/vulkan/vulkan_enums.hpp
@@ -11,6 +11,8 @@
 // include-what-you-use: make sure, vulkan.hpp is used by code-completers
 // IWYU pragma: private; include "vulkan.hpp"
 
+#include <type_traits>
+
 namespace VULKAN_HPP_NAMESPACE
 {
   template <typename FlagBitsType>