RFR: 8273112: -Xloggc and -Xlog should override -verbose [v3]

[Xiaowei Lu]

> According to java 16 specifications for java command (https://docs.oracle.com/en/java/javase/16/docs/specs/man/java.html), the command line option -Xloggc should override -verbose:gc if both options are given with the same java command. However, gc information still outputs to console even if gc log file is specified.
> 
> $java -Xloggc:gc.log -verbose:gc -version
> [0.000s][warning][gc] -Xloggc is deprecated. Will use -Xlog:gc:gc.log instead.
> [0.003s][info ][gc] Using G1
> $cat gc.log
> [0.003s][info][gc] Using G1
> 
> In addition, since -Xloggc:filename is replaced by -Xlog:gc:filename, can we assume that -Xlog:gc:filename should override -verbose:gc as -Xloggc:filename? Currently, gclog still outputs to both stdout and file if -Xlog and -verbose are given with the same java command.
> 
> $java -Xlog:gc:gc.log -verbose:gc -version
> [0.003s][info][gc] Using G1
> $cat gc.log
> [0.003s][info][gc] Using G1
> 
> As a result, we propose to put off the log configuration of -verbose option until we are confident that there isn’t -Xloggc or -Xlog options.

Xiaowei Lu has updated the pull request incrementally with one additional commit since the last revision:

  remove code in previous commit

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/5295/files
  - new: https://git.openjdk.java.net/jdk/pull/5295/files/0681dae1..f355e598

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=5295&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=5295&range=01-02

  Stats: 10 lines in 2 files changed: 0 ins; 10 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5295.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5295/head:pull/5295

PR: https://git.openjdk.java.net/jdk/pull/5295