OpcodeDispatcher: Treat ThunkOp ExitFunction as a return

ThunkOp acts as an implicit return, mark it as such so the call-ret
stack entry from the caller is popped

FEXCore/Source/Interface/Core/OpcodeDispatcher.cpp

@@ -126,7 +126,7 @@ void OpDispatchBuilder::ThunkOp(OpcodeArgs) {
   auto NewRIP = Pop(GPRSize);
 
   // Store the new RIP
-  ExitFunction(NewRIP);
+  ExitFunction(NewRIP, BranchHint::Return);
   BlockSetRIP = true;
 }