Reset in-memory JIT cache on game quit + fix Purge PPTC (#709)

Jit cache now fully resets when booting a game multiple times.
This should fix random jit cache crashes.
Also removed some redundant code related to region allocation and fixed
PPTC Purge not fully purging all PPTC files in the backup folder.

src/ARMeilleure/Translation/Cache/JitUnwindWindows.cs

@@ -52,6 +52,11 @@ namespace ARMeilleure.Translation.Cache
             nint context,
             [MarshalAs(UnmanagedType.LPWStr)] string outOfProcessCallbackDll);
 
+        [LibraryImport("kernel32.dll")]
+        [return: MarshalAs(UnmanagedType.Bool)]
+        private static unsafe partial bool RtlDeleteFunctionTable(
+            ulong tableIdentifier);
+
         private static GetRuntimeFunctionCallback _getRuntimeFunctionCallback;
 
         private static int _sizeOfRuntimeFunction;
@@ -91,6 +96,23 @@ namespace ARMeilleure.Translation.Cache
             }
         }
 
+        public static void RemoveFunctionTableHandler(nint codeCachePointer)
+        {
+            ulong codeCachePtr = (ulong)codeCachePointer.ToInt64();
+
+            bool result;
+
+            unsafe
+            {
+                result = RtlDeleteFunctionTable(codeCachePtr | 3);
+            }
+
+            if (!result)
+            {
+                throw new InvalidOperationException("Failure removing function table callback.");
+            }
+        }
+
         private static unsafe RuntimeFunction* FunctionTableHandler(ulong controlPc, nint context)
         {
             int offset = (int)((long)controlPc - context.ToInt64());