"expr_value" can be error

So that "IF" node is kept in the case below

```
def m
  if
end
```

[Feature #19013]

1 files changed, 6 insertions, 0 deletions

diff --git a/parse.y b/parse.y
index a8eadfebd3..7d830c2255 100644
--- a/parse.y
+++ b/parse.y
@@ -1901,6 +1901,12 @@ expr_value	: expr
 			value_expr($1);
 			$$ = $1;
 		    }
+		| error
+		    {
+		    /*%%%*/
+			$$ = NEW_ERROR(&@$);
+		    /*% %*/
+		    }
 		;
 
 expr_value_do	: {COND_PUSH(1);} expr_value do {COND_POP();}