Optimize vertex_shader_uid_data down to 28 bytes

This started as a fixing a misalignment issue, but I got carried away.
Was originally 41 bytes (overflowing it's expected 40 bytes by 1 bit).

Now it's 27 bytes plus 8 bits of padding (ready for future expansion).

The savings come from:
 - Removing UV usage from components, it can be reconstructed from
   texcoord_elem_count (saved 8 bits)
 - Removed the 8 unused bits from texMtxInfo_n_projection (saved 8 bits)
 - Removing unused bit from from start of components (saved 1 bit)
 - Removed extra bit from inputform, texgentype and sourcerow
 - packed texMtxInfo_n_projection and texcoord_elem_count back into
   the per texgen info space freed up above. (saved 24 bits)
 - Overlayed postMtx index and Emboss mode shifts into a union based on
   texgentype (saved 56 bits)
 - Move to a single-bit union tag, freeing up an extra bit for regular
   texgens.
 - Move PotMtx normalize into the freed up space (saved 8 bits)

Total savings: 105 bits of data

EDIT: Even worse, MSVC wasn't respecting pack(1) for bitfields at all,
      so on windows this struct was actually quite a bit larger.
      Something like 80 bytes, if not more.

      Fixed this by dropping the size of any enums used in these
      bit structs to u8. Our Common::BitField allows for the underlying
      type to be explicitly specified to something larger.

      msvc's bitfield packing appears to be completely braindead, can't
      mix sizes at all.

1 files changed, 1 insertions, 2 deletions

diff --git a/Source/Core/VideoCommon/PipelineUtils.cpp b/Source/Core/VideoCommon/PipelineUtils.cpp
index 40d9d08458..7562c99d2e 100644
--- a/Source/Core/VideoCommon/PipelineUtils.cpp
+++ b/Source/Core/VideoCommon/PipelineUtils.cpp
@@ -125,13 +125,12 @@ GXPipelineUid ApplyDriverBugs(const GXPipelineUid& in)
     vertex_shader_uid_data* vs = out.vs_uid.GetUidData();
     const PortableVertexDeclaration& decl = out.vertex_format->GetVertexDeclaration();
     vs->position_has_3_elems = decl.position.components >= 3;
-    vs->texcoord_elem_count = 0;
     for (int i = 0; i < 8; i++)
     {
       if (decl.texcoords[i].enable)
       {
         ASSERT(decl.texcoords[i].components <= 3);
-        vs->texcoord_elem_count |= decl.texcoords[i].components << (i * 2);
+        vs->texGenInfo[i].texcoord_elem_count = decl.texcoords[i].components;
       }
     }
     out.vertex_format = nullptr;