CPU/CodeCache: Clear blocks on system shutdown

Means we release all allocated memory on system shutdown, rather
than waiting until the next VM/system start.

src/core/cpu_code_cache.cpp

@@ -225,6 +225,11 @@ void CPU::CodeCache::Reset()
   }
 }
 
+void CPU::CodeCache::Shutdown()
+{
+  ClearBlocks();
+}
+
 void CPU::CodeCache::Execute()
 {
   if (IsUsingAnyRecompiler())

src/core/cpu_code_cache.h

@@ -28,6 +28,9 @@ void ProcessShutdown();
 /// Flushes the code cache, forcing all blocks to be recompiled.
 void Reset();
 
+/// Free all non-persistent resources for the code cache.
+void Shutdown();
+
 /// Invalidates all blocks which are in the range of the specified code page.
 void InvalidateBlocksWithPageIndex(u32 page_index);
 

src/core/system.cpp

@@ -1975,6 +1975,7 @@ void System::DestroySystem()
   CDROM::Shutdown();
   g_gpu.reset();
   DMA::Shutdown();
+  CPU::CodeCache::Shutdown();
   CPU::PGXP::Shutdown();
   CPU::Shutdown();
   Bus::Shutdown();