RFR: 8266038: Move newAddress() to JVMDebugger

[Yasumasa Suenaga]

SA has `newAddress()` to create `Address` instance, however it is declared in each debugger classes (e.g. `LinuxDebugger`). So we can't access it directly from `VM` class.

Before SA improvement for ZGC in [JDK-8220624](https://bugs.openjdk.java.net/browse/JDK-8220624), we need to move `newAddress()` to super class (`JVMDebugger`).

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Commit messages:
 - 8266038: Move newAddress() to JVMDebugger

Changes: https://git.openjdk.java.net/jdk/pull/3714/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3714&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8266038
  Stats: 10 lines in 5 files changed: 1 ins; 4 del; 5 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3714.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3714/head:pull/3714

PR: https://git.openjdk.java.net/jdk/pull/3714