<i18n dev> RFR: 8247781: Day periods support [v6]

[Naoto Sato]

> Hi,
> 
> Please review the changes for the subject issue. This is to enhance the java.time package to support day periods, such as "in the morning", defined in CLDR. It will add a new pattern character 'B' and its supporting builder method. The motivation and its spec are in this CSR:
> 
> https://bugs.openjdk.java.net/browse/JDK-8254629
> 
> Naoto

Naoto Sato 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 ten additional commits since the last revision:

 - Merge branch 'master' into dayperiod
 - Change based on CSR change.
 - Fixed TCK test failures, added the new pattern char description in DateTimeFormatter
 - Addressing https://github.com/openjdk/jdk/pull/938#discussion_r516147298
 - Addressing https://github.com/openjdk/jdk/pull/938#discussion_r516123190
 - Addressing https://github.com/openjdk/jdk/pull/938#discussion_r516138455
 - Fixed exception messages.
 - Addressed the following comments:
   - https://github.com/openjdk/jdk/pull/938#discussion_r515003422
   - https://github.com/openjdk/jdk/pull/938#discussion_r515005296
   - https://github.com/openjdk/jdk/pull/938#discussion_r515008862
   - https://github.com/openjdk/jdk/pull/938#discussion_r515030268
   - https://github.com/openjdk/jdk/pull/938#discussion_r515030880
   - https://github.com/openjdk/jdk/pull/938#discussion_r515032002
   - https://github.com/openjdk/jdk/pull/938#discussion_r515036803
   - https://github.com/openjdk/jdk/pull/938#discussion_r515037626
   - https://github.com/openjdk/jdk/pull/938#discussion_r515038069
   - https://github.com/openjdk/jdk/pull/938#discussion_r515039056
 - 8247781: Day periods support

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/938/files
  - new: https://git.openjdk.java.net/jdk/pull/938/files/e52fe51f..4aa5b197

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=938&range=05
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=938&range=04-05

  Stats: 12803 lines in 661 files changed: 7123 ins; 3276 del; 2404 mod
  Patch: https://git.openjdk.java.net/jdk/pull/938.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/938/head:pull/938

PR: https://git.openjdk.java.net/jdk/pull/938