<i18n dev> RFR: 8368172: Make java.time.format.DateTimePrintContext immutable [v5]

[Shaojin Wen]

> I propose to make j.t.f.DateTimePrintContext immutable.
> 
> Currently, DateTimePrintContext has only one mutable field, optional. This can be replaced by adding an optional parameter to the DateTimeFormatter.formatTo method.
> 
> Immutable DateTimePrintContext can be optimized by escape analysis, such as immutable object optimization.

Shaojin Wen has updated the pull request incrementally with one additional commit since the last revision:

  Revert "add DateTimePrinterParser#withOptional, from @RogerRiggs"
  
  This reverts commit 558fa46fa30093ff07e05e30a44ca0a86472e72e.

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Changes:
  - all: https://git.openjdk.org/jdk/pull/26913/files
  - new: https://git.openjdk.org/jdk/pull/26913/files/558fa46f..5a7e2316

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=26913&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=26913&range=03-04

  Stats: 322 lines in 2 files changed: 2 ins; 242 del; 78 mod
  Patch: https://git.openjdk.org/jdk/pull/26913.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26913/head:pull/26913

PR: https://git.openjdk.org/jdk/pull/26913