@Test public void testRuleNamesAsTree() {
		String grammar =
				"grammar T;\n" +
				"tree : 'X';";
		testErrors(new String[] { grammar, "" }, true);
	}
This is a regression test for antlr/antlr4#497 now that antlr/antlr4#309
is resolved.
https://github.com/antlr/antlr4/issues/497
https://github.com/antlr/antlr4/issues/309
tool-testsuite/test/org/antlr/v4/test/tool/TestToolSyntaxErrors.java