[Bug 54827] New: Add support for ddx(), ddy() intrinsics

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=54827

Bug ID: 54827
           Summary: Add support for ddx(), ddy() intrinsics
           Product: vkd3d
           Version: 1.7
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: hlsl
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

As you might expect, these are used by MojoShader for DSX and DSY.

Unlike the other reports I don't have a test immediately available since I
don't think I've run into this one before, but I imagine this isn't much more
than a direct translation to a common binary operation.

This uncompiled effect file is the closest thing I have to a real-world case:

https://github.com/sq/Libraries/blob/master/Squared/RenderLib/Shaders/Gaussi...