remove mcounteren in M-mode only platform

incl/iss/arch/riscv_hart_m_p.h

@@ -362,8 +362,8 @@ riscv_hart_m_p<BASE>::riscv_hart_m_p()
     csr_rd_cb[mie] = &this_class::read_ie;
     csr_wr_cb[mie] = &this_class::write_ie;
     csr_rd_cb[mhartid] = &this_class::read_hartid;
-    csr_rd_cb[mcounteren] = &this_class::read_null;
-    csr_wr_cb[mcounteren] = &this_class::write_null;
+//    csr_rd_cb[mcounteren] = &this_class::read_null;
+//    csr_wr_cb[mcounteren] = &this_class::write_null;
     csr_wr_cb[misa] = &this_class::write_null;
     csr_wr_cb[mvendorid] = &this_class::write_null;
     csr_wr_cb[marchid] = &this_class::write_null;

src/vm/interp/vm_tgc_c.cpp

@@ -4138,8 +4138,8 @@ typename vm_base<ARCH>::virt_addr_t vm_impl<ARCH>::execute_inst(finish_cond_e co
             this->do_sync(POST_SYNC, std::numeric_limits<unsigned>::max());
             pc.val = super::core.enter_trap(std::numeric_limits<uint64_t>::max(), pc.val, 0);
         } else {
-            if (is_jump_to_self_enabled(cond) && (insn == 0x0000006f || (insn&0xffff)==0xa001))
-                throw simulation_stopped(0); // 'J 0' or 'C.J 0'
+            if (is_jump_to_self_enabled(cond) &&
+                    (insn == 0x0000006f || (insn&0xffff)==0xa001)) throw simulation_stopped(0); // 'J 0' or 'C.J 0'
             auto f = decode_inst(insn);
             pc = (this->*f)(pc, insn);
         }