RFR[9] 8068686: Remove meta-index support

[Chris Hegarty]

The Modular Run-Time image, integrated in b41, no longer has JAR files,
see JEP 220 [1], The meta-index is no longer generated or used. This
issue proposes to remove the meta-index support from the runtime and
the build.

http://cr.openjdk.java.net/~chegar/8068686/
https://bugs.openjdk.java.net/browse/JDK-8068686

-Chris.

[1] https://bugs.openjdk.java.net/browse/JDK-8061971