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/ILOpCodeLoadField.cs

@@ -5,7 +5,7 @@ namespace ChocolArm64.Translation
 {
     struct ILOpCodeLoadField : IILEmit
     {
-        public FieldInfo Info { get; private set; }
+        public FieldInfo Info { get; }
 
         public ILOpCodeLoadField(FieldInfo info)
         {