Fix file_extension and file_identifier declarations
Fix file_extension and file_identifier declarations

This commit fixes parsing of `file_extension` and `file_identifier` declarations. Without semicolon expectation parser will end up prematurely upon first declaration inspection.
antlr/grammars-v4,antlr/grammars-v4,antlr/grammars-v4,antlr/grammars-v4,antlr/grammars-v4,antlr/grammars-v4,antlr/grammars-v4,antlr/grammars-v4,antlr/grammars-v4,antlr/grammars-v4,antlr/grammars-v4,antlr/grammars-v4