Fixed #2296
Fixed #2296

Visited set is now passed across internal invocations of Grammar#loadImportedGrammars of each imported grammar, to retain the knowledge if imported sets.

Signed-off-by: aermicioi <05cb2ebba8860dcaeb329f4020e4c6bd3d17e6bf@gmail.com>

parrt/antlr4,antlr/antlr4,parrt/antlr4,parrt/antlr4,ericvergnaud/antlr4,parrt/antlr4,ericvergnaud/antlr4,antlr/antlr4,ericvergnaud/antlr4,antlr/antlr4,ericvergnaud/antlr4,ericvergnaud/antlr4,antlr/antlr4,parrt/antlr4,antlr/antlr4,antlr/antlr4,ericvergnaud/antlr4,ericvergnaud/antlr4,parrt/antlr4,parrt/antlr4,antlr/antlr4,ericvergnaud/antlr4,parrt/antlr4,antlr/antlr4,ericvergnaud/antlr4,parrt/antlr4,parrt/antlr4,ericvergnaud/antlr4,antlr/antlr4,antlr/antlr4