runtime(java): Match annotation- and interface-type names of "java.lang"

runtime(java): Match annotation- and interface-type names of "java.lang"

Complement the documented support for the recognition of all
public types of the "java.lang" package (":help java.vim").
(The original syntax item generator may have, inadvertently,
contributed via suppressing "NullPointerException"s to not
having annotation and interface types qualify in general.)

Also, re-link usage instructions for the alternative syntax
item generator to a rolling "master"'s version.

closes: #17419

Signed-off-by: Aliaksei Budavei <0x000c70@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>