video_core: Rewrite the texture cache

The current texture cache has several points that hurt maintainability
and performance. It's easy to break unrelated parts of the cache
when doing minor changes. The cache can easily forget valuable
information about the cached textures by CPU writes or simply by its
normal usage.The current texture cache has several points that hurt
maintainability and performance. It's easy to break unrelated parts
of the cache when doing minor changes. The cache can easily forget
valuable information about the cached textures by CPU writes or simply
by its normal usage.

This commit aims to address those issues.

src/video_core/memory_manager.cpp

@@ -57,7 +57,10 @@ void MemoryManager::Unmap(GPUVAddr gpu_addr, std::size_t size) {
     }
 
     // Flush and invalidate through the GPU interface, to be asynchronous if possible.
-    system.GPU().FlushAndInvalidateRegion(*GpuToCpuAddress(gpu_addr), size);
+    const std::optional<VAddr> cpu_addr = GpuToCpuAddress(gpu_addr);
+    ASSERT(cpu_addr);
+
+    rasterizer->UnmapMemory(*cpu_addr, size);
 
     UpdateRange(gpu_addr, PageEntry::State::Unmapped, size);
 }