RFR: 8334742: Change java.time month/day field types to 'byte' [v2]

[Gautham Krishnan]

> In the following classes, month and day values are stored in fields of type 'int' or 'short'. The range of allowed values is small enough that the type can be 'byte' instead.
> 
> java.time.YearMonth
> java.time.MonthDay
> java.time.LocalDate
> java.time.chono.HijrahDate
> 
> Refactoring the type will give the JVM a little more layout flexibility, and will be especially useful when these classes become value classes.

Gautham Krishnan has updated the pull request incrementally with one additional commit since the last revision:

  Updating copyright header

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Changes:
  - all: https://git.openjdk.org/jdk/pull/24975/files
  - new: https://git.openjdk.org/jdk/pull/24975/files/e198afb2..148c3834

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24975&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24975&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/24975.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24975/head:pull/24975

PR: https://git.openjdk.org/jdk/pull/24975