[trace] introduce trace failed to Ext (#11019)

* [trace] add trace_failed to Ext, manage stack of trace data

* [evm] call trace_failed only if self.do_trace

* [evm] add a comment about do_trace set to true

* [vm] improve the doc in trace_prepare_execute

* [trace] add the bounds check back

ethcore/machine/src/externalities.rs

@@ -440,6 +440,10 @@ impl<'a, T: 'a, V: 'a, B: 'a> Ext for Externalities<'a, T, V, B>
 		self.vm_tracer.trace_prepare_execute(pc, instruction, gas_cost, mem_written, store_written)
 	}
 
+	fn trace_failed(&mut self) {
+		self.vm_tracer.trace_failed();
+	}
+
 	fn trace_executed(&mut self, gas_used: U256, stack_push: &[U256], mem: &[u8]) {
 		self.vm_tracer.trace_executed(gas_used, stack_push, mem)
 	}