Uniforms/constants aren't shared in D3D, let's not pretend they are.
D3D: Use fixed constant registers for pixel shader constants
D3D: Use fixed constant registers for vertex shaders too.
Some renaming
DX9: Not much point in tracking dirtiness per shader now that all constants are shared.
DX9: "Linked" shaders are now pointless, so remove them.
D3D: Assorted cleanup. Add a missing register specification.
Bind the alphatest tex after we know vert alpha.

Before we sometimes thought alpha test was trivially true when it wasn't.
Replace frame download in Sakurasou No Pet Na Kanojo
Merge pull request #6879 from unknownbrackets/gpu-minor

Bind the alphatest tex after we know vert alpha
armjit: Fix rounding mode, allow non flush-to-zero.

Default: force flush to zero (for RunFast mode.)  But now it's an ini
option so we can more easily compare armjit differences.
Merge pull request #6882 from unknownbrackets/jit-minor

armjit: Fix rounding mode, allow non flush-to-zero
Merge pull request #6873 from hrydgard/d3d-shader-cleanup

D3D shader cleanup - remove LinkedShaders and use fixed constant slots
Fix a wrong condition
Merge pull request #6884 from chinhodado/patch-4

Fix a wrong condition
Add option to vertexdecoder to expand UVs to floats
Delete the DX9 vertex decoder, use the "GL" one instead (now common)
Move vertexdecoder files into GPU/Common
Jit the most common of the "ToFloat" texcoord conversions
D3D vtxdec: Convert weights and normals to float