[jdk11u-dev] RFR: 8209935: Test to cover CodeSource.getCodeSigners() [v2]

[Goetz Lindenmaier]

> I backport this for parity with 11.0.19-oracle.

Goetz Lindenmaier 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 two additional commits since the last revision:

 - Merge branch 'openjdk:master' into GoeLin-backport-0cb0ecf4
 - Backport 0cb0ecf4433f1054ba2f0fbdabee01323893e0fe

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

Changes:
  - all: https://git.openjdk.org/jdk11u-dev/pull/1697/files
  - new: https://git.openjdk.org/jdk11u-dev/pull/1697/files/211e730b..34d4fb71

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=1697&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=1697&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/1697.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev pull/1697/head:pull/1697

PR: https://git.openjdk.org/jdk11u-dev/pull/1697