RFR: 8284313: Improve warning messages when CDS archive fails to load [v3]

[Calvin Cheung]

> Please review this change for adding more helpful messages when a CDS archive has failed to load without CDS logging being enabled.
> 
> e.g. warning for mismatch class paths between dump time and run time:
> `[warning][cds] shared class paths mismatch (hint: enable -Xlog:class+path=info to diagnose the failure)`
> 
> warning if a timestamp of a jar file has been changed during run time:
> `[warning][cds] app.jar timestamp has changed.`
> 
> Passed mach5 tiers 1,2,3 testing.

Calvin Cheung has updated the pull request incrementally with one additional commit since the last revision:

  more comments from David

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/9823/files
  - new: https://git.openjdk.org/jdk/pull/9823/files/64c7aa16..08dc3a15

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=9823&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=9823&range=01-02

  Stats: 7 lines in 2 files changed: 0 ins; 3 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/9823.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9823/head:pull/9823

PR: https://git.openjdk.org/jdk/pull/9823