[d3d9] Saturate viewport depth range

Viewport depth range in D3D9 is clamped at 0-1, same as OpenGL.

Drivers like RADV, etc support VK_EXT_depth_range_unrestricted,
which makes the regular UB of this actually work -- which isn't what
we want.

We also don't enable VK_EXT_depth_range_unrestricted, so we shouldn't
be setting depth ranges outside of the 0-1 bounds anyway.

Closes: #2960

src/d3d9/d3d9_device.cpp

@@ -5636,7 +5636,8 @@ namespace dxvk {
     viewport = VkViewport{
       float(vp.X)     + cf,    float(vp.Height + vp.Y) + cf,
       float(vp.Width),        -float(vp.Height),
-      vp.MinZ,                 std::max(vp.MaxZ, vp.MinZ + zBias),
+      std::clamp(vp.MinZ,                            0.0f, 1.0f),
+      std::clamp(std::max(vp.MaxZ, vp.MinZ + zBias), 0.0f, 1.0f),
     };
 
     // Scissor rectangles. Vulkan does not provide an easy way