RFR: 8268124: Update java.lang to use switch expressions [v4]

[Patrick Concannon]

> Hi,
> 
> Could someone please review my code for updating the code in the `java.lang` packages to make use of the switch expressions?
> 
> Kind regards,
> Patrick

Patrick Concannon 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 four additional commits since the last revision:

 - Merge remote-tracking branch 'origin/master' into JDK-8268124
 - 8268124: small refactoring; fixed misplaced comment and added missing lambda operator
 - Merge remote-tracking branch 'origin/master' into JDK-8268124
 - 8268124: Update java.lang to use switch expressions

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/4312/files
  - new: https://git.openjdk.java.net/jdk/pull/4312/files/a8706b02..7907f3eb

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=4312&range=03
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=4312&range=02-03

  Stats: 463928 lines in 821 files changed: 455007 ins; 5063 del; 3858 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4312.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4312/head:pull/4312

PR: https://git.openjdk.java.net/jdk/pull/4312