Vulkan update/NVAPI support (#1511)

* First pass at incorporating nvapi into test harness.

* D3d12 Atomic Float Add via NVAPI working

* Dx12 atomic float appears to work.

* Atomic float add on Dx12.

* Added atomic64 feature addition to vk.
Fix correct output for atomic-float-byte-address.slang

* Disable atomic float failing tests.

* Upgraded VK headers.

* Detect atomic float availability on VK.

* Try to get test working for in64 atomic.

* Made HLSL prelude controlled via the render-test requirements.

* Added -enable-nvapi to premake.

* Fix D3D12Renderer when NVAPI is not available.

* Small improvements to VKRenderer.

* Improve atomic documentation in target-compatibility.md.

1 files changed, 19 insertions, 0 deletions

diff --git a/tools/gfx/nvapi/nvapi-util.h b/tools/gfx/nvapi/nvapi-util.h
new file mode 100644
index 000000000..704f4ede4
--- /dev/null
+++ b/tools/gfx/nvapi/nvapi-util.h
@@ -0,0 +1,19 @@
+// nvapi-util.h
+#pragma once
+
+#include "../../slang-com-helper.h"
+#include "../../slang-com-ptr.h"
+
+namespace gfx {
+
+struct NVAPIUtil
+{
+        /// Set up NVAPI for use. Must be called before any other function is used.
+    static SlangResult initialize();
+        /// True if the NVAPI is available, can be called even if initialize fails.
+        /// If initialize has not been called will return false
+    static bool isAvailable();
+};
+
+
+} // gfx