Test case for issue #2173: https://github.com/typetools/checker-framework/issues/2173

ImporterManager.class was compiled using a Java 8 compiler.  The compiler copied
the annotation from a lambda to a method parameter type argument, but the
parameter does not have a type argument.  This bug has been fixed in Java 9,
but bytecode generated by Java 8 can still be read by a checker, so this tests
that it won't crash a checker.