Interpreter: Drop idle skipping in interpreter.

And reimplement it in the cached interpreter based on the idle loop detection.

Source/Core/Core/PowerPC/CachedInterpreter/CachedInterpreter.cpp

@@ -181,6 +181,15 @@ static bool CheckBreakpoint(u32 data)
   return false;
 }
 
+static bool CheckIdle(u32 idle_pc)
+{
+  if (PowerPC::ppcState.npc == idle_pc)
+  {
+    CoreTiming::Idle();
+  }
+  return false;
+}
+
 bool CachedInterpreter::HandleFunctionHooking(u32 address)
 {
   return HLE::ReplaceFunctionIfPossible(address, [&](u32 function, HLE::HookType type) {
@@ -242,6 +251,7 @@ void CachedInterpreter::Jit(u32 address)
       const bool check_fpu = (op.opinfo->flags & FL_USE_FPU) && !js.firstFPInstructionFound;
       const bool endblock = (op.opinfo->flags & FL_ENDBLOCK) != 0;
       const bool memcheck = (op.opinfo->flags & FL_LOADSTORE) && jo.memcheck;
+      const bool idle_loop = op.branchIsIdleLoop;
 
       if (breakpoint)
       {
@@ -261,6 +271,8 @@ void CachedInterpreter::Jit(u32 address)
       m_code.emplace_back(PPCTables::GetInterpreterOp(op.inst), op.inst);
       if (memcheck)
         m_code.emplace_back(CheckDSI, js.downcountAmount);
+      if (idle_loop)
+        m_code.emplace_back(CheckIdle, js.blockStart);
       if (endblock)
         m_code.emplace_back(EndBlock, js.downcountAmount);
     }