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/nested-arrays.shader_test

@@ -0,0 +1,25 @@
+[pixel shader fail]
+uniform float4 color[2][3];
+
+float4 main() : sv_target
+{
+    return color[2][1];
+}
+
+[pixel shader]
+uniform float color[2][3];
+
+float4 main() : sv_target
+{
+    return float4(color[1][0], color[0][0], color[1][2], color[0][2]);
+}
+
+[test]
+uniform  0 float4 0.1 0.0 0.0 0.0
+uniform  4 float4 0.2 0.0 0.0 0.0
+uniform  8 float4 0.3 0.0 0.0 0.0
+uniform 12 float4 0.4 0.0 0.0 0.0
+uniform 16 float4 0.5 0.0 0.0 0.0
+uniform 20 float4 0.6 0.0 0.0 0.0
+draw quad
+probe all rgba (0.4, 0.1, 0.6, 0.3)