RFR: 8279986: methods Math::asXExact for safely checked primitive casts [v2]

[Raffaello Giulietti]

> Add a family of "safe" cast methods.

Raffaello Giulietti 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:

 - 8279986: methods Math::asXExact for safely checked primitive casts
   
   Merge branch 'master' into JDK-8279986
 - 8279986: methods Math::asXExact for safely checked primitive casts
   
   Merge branch 'master' into JDK-8279986
 - 8279986: methods Math::asXExact for safely checked primitive casts
 - 8279986: methods Math::asXExact for safely checked primitive casts

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8548/files
  - new: https://git.openjdk.java.net/jdk/pull/8548/files/4d0924c5..7be0f9de

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8548&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8548&range=00-01

  Stats: 103190 lines in 1255 files changed: 93727 ins; 4219 del; 5244 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8548.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8548/head:pull/8548

PR: https://git.openjdk.java.net/jdk/pull/8548