RFR: 8265972: Remove declarations with no implementations in javaClasses.hpp

[Albert Mingkun Yang]

Trivial change of removing dead code.

-------------

Commit messages:
 - classes

Changes: https://git.openjdk.java.net/jdk/pull/3692/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3692&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8265972
  Stats: 10 lines in 1 file changed: 0 ins; 10 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3692.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3692/head:pull/3692

PR: https://git.openjdk.java.net/jdk/pull/3692