RFR: 8299518: HotSpotVirtualMachine shared code across different platforms [v5]

[Yi Yang]

> harmless refactor to share code across different platforms of VirtualMachineImpl:
> 1. Shared code to process command response after requesting a command execution
> 2. Read functionality in SocketInputStream can be reused

Yi Yang has updated the pull request incrementally with one additional commit since the last revision:

  Update src/jdk.attach/share/classes/sun/tools/attach/HotSpotVirtualMachine.java
  
  Co-authored-by: Andrey Turbanov <turbanoff at gmail.com>

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/11823/files
  - new: https://git.openjdk.org/jdk/pull/11823/files/e9d8c36f..9d6aa99f

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=11823&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=11823&range=03-04

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/11823.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11823/head:pull/11823

PR: https://git.openjdk.org/jdk/pull/11823