RFR: 8314491: Linux: jexec launched via PATH fails to find java [v6]

[Vladimir Petko]

> 8314491: Linux: jexec launched via PATH fails to find java

Vladimir Petko has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains eight additional commits since the last revision:

 - Merge branch 'master' into 8314491-jexec-resolve-symlink
 - declare error in-place
 - remove unused imports
 - Review comment: use /proc/self/exe as the backup option
 - Merge branch 'master' into 8314491-jexec-resolve-symlink
 - correct copyright statement
 - Use /proc/self/exec to identify path to the executable.
 - Create failing test for jexec in PATH issue

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Changes:
  - all: https://git.openjdk.org/jdk/pull/15343/files
  - new: https://git.openjdk.org/jdk/pull/15343/files/c974e011..5354ceba

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15343&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15343&range=04-05

  Stats: 4629 lines in 273 files changed: 3398 ins; 519 del; 712 mod
  Patch: https://git.openjdk.org/jdk/pull/15343.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15343/head:pull/15343

PR: https://git.openjdk.org/jdk/pull/15343