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/numeric-constructor-truncation.shader_test

@@ -0,0 +1,33 @@
+[pixel shader]
+float4 main() : sv_target
+{
+    float3 x = float4(71, 72, 73, 74);
+    return float4(x, 75);
+}
+
+[test]
+draw quad
+probe all rgba (71.0, 72.0, 73.0, 75.0)
+
+
+[pixel shader]
+struct stu
+{
+    float aa;
+    float2 bb;
+    float cc;
+};
+
+float4 main() : sv_target
+{
+    struct stu foo;
+    foo.cc = 5;
+    foo.bb = float3(2, 3, 4); // It shall not overflow to cc;
+    foo.aa = 1;
+
+    return float4(foo);
+}
+
+[test]
+draw quad
+probe all rgba (1.0, 2.0, 3.0, 5.0)