RFR: 8284849: Add deoptimization to unified logging

[Johan Sjölén]

This PR adds a new "deoptimization" tag and a new log message on the info level mimicking JFR's deoptimization event. In the future this tag will be used to add trace level information, hopefully replacing TraceDeoptimization. JFR's event also captures the stacktrace, which this does not (happy to add this if considered important).

An example output looks like this: 


[1.346s][info][deoptimization] Deoptimization start {
[1.346s][info][deoptimization]   compileId = 407
[1.346s][info][deoptimization]   compiler = c2
[1.346s][info][deoptimization]   method:lineno:bci = java.util.concurrent.locks.ReentrantLock$Sync.tryRelease(I)Z:176:26
[1.346s][info][deoptimization]   instruction = ifne
[1.346s][info][deoptimization]   reason = unstable_if
[1.346s][info][deoptimization]   action = reinterpret
[1.346s][info][deoptimization] } Deoptimization end

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

Commit messages:
 - Move logLevel include
 - Add UL logging of deoptimization event

Changes: https://git.openjdk.java.net/jdk/pull/8812/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8812&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8284849
  Stats: 17 lines in 2 files changed: 17 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8812.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8812/head:pull/8812

PR: https://git.openjdk.java.net/jdk/pull/8812