Using label with repeated rule and equal (=) operator

[Ivan Kochurkin]

ANTLR supports rule labels. We can use them by the following way:

rule1
    : t1 = a
    ;

For multiple elements we can use the following syntax with += operator:

rule1
    : t1 += a+
    ;

But If we wil use a usual = operator with multiple elements:

rule1
    : t1 = a+
    ;

t1 rule will point on the last element of a+ sequence. Should we generate a error in this case or t1 must point on array as in second case?

See also this issue: https://github.com/antlr/antlr4/issues/1409