RFR: 8283782: Redundant verification of year in LocalDate::ofEpochDay

[Claes Redestad]

In `LocalDate::ofEpochDays` we validate the epoch day input, then we also validate the year derived from that value. This second validation is redundant since the minimum and maximum valid epoch day line up with the first and last day of the minimum and maximum valid year, respectively. This patch replace this redundant runtime validation with a test. 

This reduces code complexity (increasing chance for inlining to happen) and removes a couple of branches from generated code.

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Commit messages:
 - Explicitly check that year in successfully created LocalDates is valid
 - Copyright
 - Redundant verification of year in LocalDate::ofEpochDay

Changes: https://git.openjdk.java.net/jdk/pull/8014/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8014&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8283782
  Stats: 38 lines in 2 files changed: 33 ins; 2 del; 3 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8014.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8014/head:pull/8014

PR: https://git.openjdk.java.net/jdk/pull/8014