Highlight cross references for grammar rules with multiple definitions

[rillig]

In a grammar, I have these lines:

%%
start : program { }
program : { }
program : { }

When I select the word program in line 2 or 3, the other one is highlighted as well, just as expected.

When I select the word program in line 4, the other ones in lines 2 and 3 are not highlighted, even though they refer to the same grammar rule.

By the way, thank you for the plugin, it's great that the plugin is also useful for C grammars like for Bison and Yacc, even though this is not the plugin's primary goal.