tests: Move HLSL tests to a subdirectory.

Approved-by: Giovanni Mascellani (@giomasce)
Approved-by: Francisco Casas (@fcasas)
Approved-by: Henri Verbeet (@hverbeet)
Approved-by: Alexandre Julliard (@julliard)
Merge-Request: https://gitlab.winehq.org/wine/vkd3d/-/merge_requests/248

tests/hlsl/distance.shader_test

@@ -0,0 +1,23 @@
+[pixel shader]
+uniform float4 x;
+uniform float4 y;
+
+float4 main() : sv_target
+{
+    return distance(x, y);
+}
+
+[test]
+uniform 0 float4 -2.0 3.0 4.0 0.1
+uniform 4 float4 2.0 -1.0 4.0 5.0
+draw quad
+probe all rgba (7.483983, 7.483983, 7.483983, 7.483983) 1
+
+[pixel shader]
+uniform int4 x;
+uniform int4 y;
+
+float4 main() : sv_target
+{
+    return distance(x, y);
+}