Fixup DFG check condition

Author: nielsdos

Zend/Optimizer/zend_dfg.c

@@ -152,7 +152,6 @@ static zend_always_inline void _zend_dfg_add_use_def_op(const zend_op_array *op_
 		case ZEND_BIND_STATIC:
 		case ZEND_SEND_VAR_NO_REF:
 		case ZEND_SEND_VAR_NO_REF_EX:
-		case ZEND_SEND_VAR:
 		case ZEND_SEND_VAR_EX:
 		case ZEND_SEND_FUNC_ARG:
 		case ZEND_SEND_REF:
@@ -174,6 +173,11 @@ static zend_always_inline void _zend_dfg_add_use_def_op(const zend_op_array *op_
 				goto add_op1_def;
 			}
 			break;
+		case ZEND_SEND_VAR:
+			if (opline->op1_type == IS_CV && ((build_flags & ZEND_SSA_RC_INFERENCE) || opline->op2_type == IS_UNUSED)) {
+				goto add_op1_def;
+			}
+			break;
 		case ZEND_CAST:
 		case ZEND_QM_ASSIGN:
 		case ZEND_JMP_SET: