Misc. CPU improvements (#519)

* Fix and simplify TranslatorCache

* Fix some assignment alignments, remove some unused usings

* Changes to ILEmitter, separate it from ILEmitterCtx

* Rename ILEmitter to ILMethodBuilder

* Rename LdrLit and *_Fix opcodes

* Revert TranslatorCache impl to the more performant one, fix a few issues with it

* Allow EmitOpCode to be called even after everything has been emitted

* Make Emit and AdvanceOpCode private, simplify it a bit now that it starts emiting from the entry point

* Remove unneeded temp use

* Add missing exit call on TestExclusive

* Use better hash

* Implement the == and != operators

ChocolArm64/Decoders/ShiftType.cs

@@ -2,9 +2,9 @@ namespace ChocolArm64.Decoders
 {
     enum ShiftType
     {
-        Lsl,
-        Lsr,
-        Asr,
-        Ror
+        Lsl = 0,
+        Lsr = 1,
+        Asr = 2,
+        Ror = 3
     }
 }