Add shaders re-implemented in HLSL

These were written against the shaders at revision eddd724e7.
There have been changes made since then, which will need to be mirrored.

See `data/hlsl/README.md` for the current status of each sample.

data/hlsl/nv_ray_tracing_basic/miss.rmiss

@@ -0,0 +1,12 @@
+// Copyright 2020 Google LLC
+
+struct Payload
+{
+[[vk::location(0)]] float3 hitValue;
+};
+
+[shader("miss")]
+void main(inout Payload p)
+{
+    p.hitValue = float3(0.0, 0.0, 0.2);
+}