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/struct-semantics.shader_test

@@ -0,0 +1,52 @@
+[input layout]
+0 r32g32b32a32 float texcoord
+0 r32g32 float sv_position
+
+[vertex buffer 0]
+0.0 1.0 0.0 1.0   -2.0 -2.0
+0.0 1.0 0.0 1.0   -2.0  2.0
+0.0 1.0 0.0 1.0    2.0 -2.0
+0.0 1.0 0.0 1.0    2.0  2.0
+
+[vertex shader]
+
+struct vertex
+{
+    struct
+    {
+        float4 texcoord : texcoord;
+        float4 pos : sv_position;
+    } m;
+};
+
+void main(inout struct vertex v)
+{
+}
+
+[pixel shader]
+struct input
+{
+    struct
+    {
+        float4 texcoord : texcoord;
+    } m;
+};
+
+struct output
+{
+    struct
+    {
+        float4 color : sv_target;
+    } m;
+};
+
+struct output main(struct input i)
+{
+    struct output o;
+    o.m.color = i.m.texcoord;
+    return o;
+}
+
+[test]
+draw triangle strip 4
+probe all rgba (0.0, 1.0, 0.0, 1.0)