RFR: 8284849: Add deoptimization to unified logging [v6]

[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

Johan Sjölén has updated the pull request incrementally with two additional commits since the last revision:

 - Simplify code
 - Refactor using LogStream

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8812/files
  - new: https://git.openjdk.java.net/jdk/pull/8812/files/c269810c..1eddf482

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8812&range=05
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8812&range=04-05

  Stats: 37 lines in 2 files changed: 17 ins; 9 del; 11 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