maxwell_3d: Allow texture handles with TIC id zero

Also remove "enabled" field from Tegra::Texture::FullTextureInfo because
it would become unused.

src/video_core/engines/maxwell_3d.cpp

@@ -462,13 +462,9 @@ std::vector<Texture::FullTextureInfo> Maxwell3D::GetStageTextures(Regs::ShaderSt
             sizeof(Texture::TextureHandle);
 
         // Load the TIC data.
-        if (tex_handle.tic_id != 0) {
-            tex_info.enabled = true;
-
         auto tic_entry = GetTICEntry(tex_handle.tic_id);
         // TODO(Subv): Workaround for BitField's move constructor being deleted.
         std::memcpy(&tex_info.tic, &tic_entry, sizeof(tic_entry));
-        }
 
         // Load the TSC data
         if (tex_handle.tsc_id != 0) {
@@ -477,7 +473,6 @@ std::vector<Texture::FullTextureInfo> Maxwell3D::GetStageTextures(Regs::ShaderSt
             std::memcpy(&tex_info.tsc, &tsc_entry, sizeof(tsc_entry));
         }
 
-        if (tex_info.enabled)
         textures.push_back(tex_info);
     }
 
@@ -501,13 +496,9 @@ Texture::FullTextureInfo Maxwell3D::GetStageTexture(Regs::ShaderStage stage,
     tex_info.index = static_cast<u32>(offset);
 
     // Load the TIC data.
-    if (tex_handle.tic_id != 0) {
-        tex_info.enabled = true;
-
     auto tic_entry = GetTICEntry(tex_handle.tic_id);
     // TODO(Subv): Workaround for BitField's move constructor being deleted.
     std::memcpy(&tex_info.tic, &tic_entry, sizeof(tic_entry));
-    }
 
     // Load the TSC data
     if (tex_handle.tsc_id != 0) {

src/video_core/renderer_opengl/gl_rasterizer.cpp

@@ -1008,10 +1008,6 @@ void RasterizerOpenGL::SetupTextures(Maxwell::ShaderStage stage, const Shader& s
         auto& unit = state.texture_units[current_bindpoint];
 
         const auto texture = maxwell3d.GetStageTexture(entry.GetStage(), entry.GetOffset());
-        if (!texture.enabled) {
-            unit.texture = 0;
-            continue;
-        }
 
         texture_samplers[current_bindpoint].SyncWithConfig(texture.tsc);
 

src/video_core/textures/texture.h

@@ -317,7 +317,6 @@ struct FullTextureInfo {
     u32 index;
     TICEntry tic;
     TSCEntry tsc;
-    bool enabled;
 };
 
 /// Returns the number of bytes per pixel of the input texture format.