[GPU] 3d-to-2d textures default enable

Replaced the modal cvar with bool gpu_3d_to_2d_texture with "mode 2" now enabled by
default and "mode 1" removed as unnecessary

src/xenia/gpu/texture_cache.h

@@ -251,6 +251,11 @@ class TextureCache {
       return guest_layout().mips_total_extent_bytes;
     }
 
+    // For 3D-as-2D wrappers: the host texture is 2D but we need 3D tiling
+    // when loading from guest memory.
+    bool force_load_3d_tiling() const { return force_load_3d_tiling_; }
+    void SetForceLoad3DTiling(bool force) { force_load_3d_tiling_ = force; }
+
     uint64_t GetHostMemoryUsage() const { return host_memory_usage_; }
 
     uint64_t last_usage_submission_index() const {
@@ -323,6 +328,10 @@ class TextureCache {
     // Set to false via constructor for wrapper textures.
     bool in_usage_list_;
 
+    // For 3D-as-2D wrappers: use 3D tiling when loading even though the host
+    // texture is 2D.
+    bool force_load_3d_tiling_ = false;
+
     // Whether the most up-to-date base / mips contain pages with data from a
     // resolve operation (rather than from the CPU or memexport), primarily for
     // choosing between piecewise linear gamma and sRGB when the former is