Core/Jits: Adds an option to disable the register cache.

This will help to disable all inter-instruction dependencies.
So android users can check if only a single instruction is broken without compiling dolphin on their own.

Source/Core/Core/ConfigManager.h

@@ -105,6 +105,7 @@ struct SConfig
   bool bJITPairedOff = false;
   bool bJITSystemRegistersOff = false;
   bool bJITBranchOff = false;
+  bool bJITRegisterCacheOff = false;
 
   bool bFastmem;
   bool bFPRF = false;