[cpp] reset line change at beginning of while block

src/generators/gencpp.ml

@@ -3260,7 +3260,6 @@ let gen_cpp_ast_expression_tree ctx class_name func_name function_args function_
          List.iter gen_closure closures;
          (match injection with Some inject -> inject.inj_prologue gc_stack | _ -> () );
          let remaining = ref (List.length exprs) in
-         lastLine := Lexer.get_error_line tree.epos;
          List.iter (fun e ->
             output_p e "";
             if (!remaining=1) then
@@ -3769,9 +3768,11 @@ let gen_cpp_ast_expression_tree ctx class_name func_name function_args function_
           (match while_flag with
           | NormalWhile ->
               out "while("; gen condition; out (")");
+              lastLine := -1;
               gen block;
           | DoWhile ->
               out ("do ");
+              lastLine := -1;
               gen block;
               out "while("; gen condition; out ")"
           );