RFR: 8256692: Zero: remove obsolete block from ZeroInterpreter::native_entry

[Aleksey Shipilev]

There is a block that is protected by #if 0. Seems to be protected by it after [JDK-8239782](https://bugs.openjdk.java.net/browse/JDK-8256692), and it is completely unnecessary after [JDK-8255617](https://bugs.openjdk.java.net/browse/JDK-8255617).

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

Commit messages:
 - 8256692: Zero: remove obsolete block from ZeroInterpreter::native_entry

Changes: https://git.openjdk.java.net/jdk/pull/1328/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1328&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8256692
  Stats: 20 lines in 1 file changed: 0 ins; 20 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1328.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1328/head:pull/1328

PR: https://git.openjdk.java.net/jdk/pull/1328