RFR: 8279986: methods Math::asXExact for safely checked primitive casts [v6]

[Raffaello Giulietti]

> Add a family of "safe" cast methods.

Raffaello Giulietti has updated the pull request incrementally with one additional commit since the last revision:

  8279986: methods Math::asXExact for safely checked primitive casts

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8548/files
  - new: https://git.openjdk.java.net/jdk/pull/8548/files/5fb1fed4..4cf9a8cf

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8548&range=05
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8548&range=04-05

  Stats: 6 lines in 2 files changed: 0 ins; 0 del; 6 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