[lworld] RFR: 8373826: [lworld] Test PreviewAutoSuppress fails since jimage change [v2]

[Jan Lahoda]

> Fixing `test/langtools/tools/javac/diags/CheckExamples.java` (`test/langtools/tools/javac/diags/examples/PrimitivePatternMatching.java`) and `test/langtools/tools/javac/preview/PreviewAutoSuppress.java` tests.
> 
> Unfortunately, it is quite hard to make the tests work both with and without `-DDISABLE_PREVIEW_PATCHING=true` (could be done for `PreviewAutoSuppress.java`, but it is very hard to do sensible for `CheckExamples.java`), so given the future is `-DDISABLE_PREVIEW_PATCHING=true`, this change forces this option. (The practical impact of testing only this variant for these two tests is basically zero, I think. We have a different test that verifies all the combinations.)

Jan Lahoda 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 four additional commits since the last revision:

 - Removing flags that are no longer necessary.
 - Removing tests from problem list.
 - Merge remote-tracking branch 'upstream-ssh/lworld' into JDK-8373828
 - Fixing test when running with -DDISABLE_PREVIEW_PATCHING=true (and forcing a run with this option).

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

Changes:
  - all: https://git.openjdk.org/valhalla/pull/1813/files
  - new: https://git.openjdk.org/valhalla/pull/1813/files/eb89a424..e37fa48b

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=valhalla&pr=1813&range=01
 - incr: https://webrevs.openjdk.org/?repo=valhalla&pr=1813&range=00-01

  Stats: 486 lines in 80 files changed: 221 ins; 99 del; 166 mod
  Patch: https://git.openjdk.org/valhalla/pull/1813.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1813/head:pull/1813

PR: https://git.openjdk.org/valhalla/pull/1813