RFR: 8314258: checked_cast doesn't properly check some cases [v4]

[Kim Barrett]

> Please review this addition of the `integer_cast` utility.
> 
> Details in first comment, to avoid email spamming from automatic messages.
> 
> Testing: mach5 tier1-5 with `checked_cast` for integral types changed to call
> the new `integer_cast`.  Addition of `integer_cast` includes gtests.

Kim Barrett has updated the pull request incrementally with one additional commit since the last revision:

  remove comments about compiler optimization expectations

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/29582/files
  - new: https://git.openjdk.org/jdk/pull/29582/files/15e3d79e..62e24919

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=29582&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=29582&range=02-03

  Stats: 4 lines in 1 file changed: 0 ins; 2 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/29582.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29582/head:pull/29582

PR: https://git.openjdk.org/jdk/pull/29582