Refine r496923.

libinstrument.so and libjdwp.so do not need anything from $LOCALBASE but
libsplashscreen.so does. For example,

% cd /usr/local/openjdk11
% bin/java -jar demo/jfc/SwingSet2/SwingSet2.jar
ld-elf.so.1: /usr/local/openjdk11/lib/libsplashscreen.so: Undefined symbol
"libiconv_open"

PR: 236759