Misc. CPU optimizations (#575)

* Add optimizations related to caller/callee saved registers, thread synchronization and disable tier 0

* Refactoring

* Add a config entry to enable or disable the reg load/store opt.

* Remove unnecessary register state stores for calls when the callee is know

* Rename IoType to VarType

* Enable tier 0 while fixing some perf issues related to tier 0

* Small tweak -- Compile before adding to the cache, to avoid lags

* Add required config entry

ChocolArm64/Translation/CallType.cs

@@ -0,0 +1,9 @@
+namespace ChocolArm64.Translation
+{
+    enum CallType
+    {
+        Call,
+        VirtualCall,
+        VirtualJump
+    }
+}