RFR: JDK-8042981: Strip type annotations in Types' utility methods [v8]

[Joe Darcy]

> Early review for JDK-8042981: "Strip type annotations in Types' utility methods". I work more often in the Element world rather than the Type word of the annotation processing APIs.
> 
> The type annotations on primitive types are *not* cleared by the existing annotation clearing mechanisms. I suspect Type.Visitor is missing a case for primitive types. Someone with familiarity with javac's type modeling should take a look; thanks.

Joe Darcy has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 12 commits:

 - Merge branch 'master' into JDK-8042981
 - Revert changes that will be done under JDK-8323684.
 - Merge branch 'master' into JDK-8042981
 - Update implementation and tests.
 - Add changes from Liam.
 - Merge branch 'master' into JDK-8042981
 - Intermediate commit; add stripAnnotations method.
 - Merge branch 'master' into JDK-8042981
 - Merge branch 'master' into JDK-8042981
 - Update visitor; all langtools regression tests pass.
 - ... and 2 more: https://git.openjdk.org/jdk/compare/81df265e...72b9333a

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

Changes: https://git.openjdk.org/jdk/pull/8984/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=8984&range=07
  Stats: 317 lines in 5 files changed: 306 ins; 0 del; 11 mod
  Patch: https://git.openjdk.org/jdk/pull/8984.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/8984/head:pull/8984

PR: https://git.openjdk.org/jdk/pull/8984