Remove old Ziccid implementation

riscv/execute.cc

@@ -223,15 +223,6 @@ void processor_t::step(size_t n)
     }
   }
 
-  if (extension_enabled(EXT_ZICCID)) {
-    // Ziccid requires stores eventually become visible to instruction fetch,
-    // so periodically flush the I$
-    if (ziccid_flush_count-- == 0) {
-      ziccid_flush_count += ZICCID_FLUSH_PERIOD;
-      _mmu->flush_icache();
-    }
-  }
-
   while (n > 0) {
     size_t instret = 0;
     reg_t pc = state.pc;

riscv/processor.h

@@ -414,9 +414,6 @@ private:
   static const size_t OPCODE_CACHE_SIZE = 4095;
   opcode_cache_entry_t opcode_cache[OPCODE_CACHE_SIZE];
 
-  unsigned ziccid_flush_count = 0;
-  static const unsigned ZICCID_FLUSH_PERIOD = 10;
-
   void take_pending_interrupt() { take_interrupt(state.mip->read() & state.mie->read()); }
   void take_interrupt(reg_t mask); // take first enabled interrupt in mask
   void take_trap(trap_t& t, reg_t epc); // take an exception