RFR: 8370520: GenShen: Track and report on promotion failures [v3]

[William Kemper]

> Keep track of promotion failures. Report the number of failures and total number of bytes that could not be promoted. These changes were hoisted out of https://github.com/openjdk/jdk/pull/27632.

William Kemper has updated the pull request incrementally with one additional commit since the last revision:

  Change log level of detailed promotion failure message
  
  And only do the work for the message if the log level is enabled.

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Changes:
  - all: https://git.openjdk.org/jdk/pull/27962/files
  - new: https://git.openjdk.org/jdk/pull/27962/files/9213b8cb..a86e34c8

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=27962&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=27962&range=01-02

  Stats: 41 lines in 2 files changed: 17 ins; 14 del; 10 mod
  Patch: https://git.openjdk.org/jdk/pull/27962.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27962/head:pull/27962

PR: https://git.openjdk.org/jdk/pull/27962