RFR: 8267670: Update java.io, java.math, and java.text to use switch expressions [v3]

[Patrick Concannon]

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

Patrick Concannon has updated the pull request incrementally with one additional commit since the last revision:

  8267670: Remove redundant code from switch

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/4182/files
  - new: https://git.openjdk.java.net/jdk/pull/4182/files/adc8af41..e503ed26

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=4182&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=4182&range=01-02

  Stats: 24 lines in 3 files changed: 4 ins; 3 del; 17 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4182.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4182/head:pull/4182

PR: https://git.openjdk.java.net/jdk/pull/4182