RFR: 8255697: LogTargetHandle::print should check if log level is enabled

[Claes Redestad]

An early check in LogTargetHandle::print like this can reduce overhead by not dropping into code that initialize LogDecorations et.c. This saves around 100k instructions on VM bootstrap, and can reduce cost of not logging in a few places.

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Commit messages:
 - Merge branch 'master' into print_check_enabled
 - Add early check if logStreamHandle is enabled

Changes: https://git.openjdk.java.net/jdk/pull/964/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=964&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8255697
  Stats: 3 lines in 1 file changed: 2 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/964.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/964/head:pull/964

PR: https://git.openjdk.java.net/jdk/pull/964