[test] add test (closes #9899)

tests/unit/src/unit/issues/Issue9899.hx

@@ -0,0 +1,10 @@
+package unit.issues;
+
+class Issue9899 extends unit.Test {
+	function test() {
+		t(switch (macro !a is T) {
+			case {expr: EIs({expr: EUnop(_)}, _)}: true;
+			case _: false;
+		});
+	}
+}