Move `error` from top_stmts and top_stmt to stmt

By this change, syntax error is recovered smaller units.
In the case below, "DEFN :bar" is same level with "CLASS :Foo"
now.

```
module Z
  class Foo
    foo.
  end

  def bar
  end
end
```

[Feature #19013]

1 files changed, 6 insertions, 8 deletions

diff --git a/parse.y b/parse.y
index c0959a5e81..a8eadfebd3 100644
--- a/parse.y
+++ b/parse.y
@@ -1430,10 +1430,6 @@ top_stmts	: none
 		    /*% %*/
 		    /*% ripper: stmts_add!($1, $3) %*/
 		    }
-		| error top_stmt
-		    {
-			$$ = remove_begin($2);
-		    }
 		;
 
 top_stmt	: stmt
@@ -1503,10 +1499,6 @@ stmts		: none
 		    /*% %*/
 		    /*% ripper: stmts_add!($1, $3) %*/
 		    }
-		| error stmt
-		    {
-			$$ = remove_begin($2);
-		    }
 		;
 
 stmt_or_begin	: stmt
@@ -1659,6 +1651,12 @@ stmt		: keyword_alias fitem {SET_LEX_STATE(EXPR_FNAME|EXPR_FITEM);} fitem
 		    /*% ripper: massign!($1, $4) %*/
 		    }
 		| expr
+		| error
+		    {
+		    /*%%%*/
+			$$ = NEW_ERROR(&@$);
+		    /*% %*/
+		    }
 		;
 
 command_asgn	: lhs '=' lex_ctxt command_rhs