RFR: 8376665: Port fdlibm acosh to Java [v7]

[Anton Artemov]

> Hi, please consider the following changes:
> 
> This is a port of FDLIBM acosh method.

Anton Artemov has updated the pull request incrementally with two additional commits since the last revision:

 - 8376665: Stylistical fixes.
 - 8376665: Stylistical fixes.

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/29488/files
  - new: https://git.openjdk.org/jdk/pull/29488/files/dd5c5f7e..9e468d66

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=29488&range=06
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=29488&range=05-06

  Stats: 31 lines in 5 files changed: 0 ins; 2 del; 29 mod
  Patch: https://git.openjdk.org/jdk/pull/29488.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29488/head:pull/29488

PR: https://git.openjdk.org/jdk/pull/29488