RFR: 8294993: LingeredApp test update [v4]

[Kevin Walls]

> There are a few changes we can make to better understand the LingeredApp test when it goes wrong:
> 
> startAppExactJvmOpts() should not try and call finishApp unless the process isAlive, that just creates a misleading exception.
> 
> waitAppReady() is really waitAppReadyOrCrashed(), and should not timeout immediately after the 1 second sleep, or we lose a second of our timeout value (not critical with a long timeout, but seems more honest).
> 
> Show how long we waited when startup/crashing times out.
> 
> Show how long a good startup takes, so we have a basic for comparison when it fails.
> 
> Show if there are hs_err/core/mdmp files in the working directory after startup/crash attempt.
> 
> Also, in open/test/lib/jdk/test/lib/util/CoreUtils.java:
> 
> "Move core file" often seems unnecessary, core/mdmp usually being created in the current directory. But getCoreFileLocation() performs Files.move() which takes enough time to not be a no-op.

Kevin Walls has updated the pull request incrementally with one additional commit since the last revision:

  Dump file size in megabytes.

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/10613/files
  - new: https://git.openjdk.org/jdk/pull/10613/files/3fef5b77..f323d12c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=10613&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=10613&range=02-03

  Stats: 2 lines in 1 file changed: 1 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/10613.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10613/head:pull/10613

PR: https://git.openjdk.org/jdk/pull/10613