RFR: JDK-8270476: Make floating-point test infrastructure more lambda and method reference friendly [v2]

[Joe Darcy]

> Update the java.lang.{Math, StrictMath} regression test helper library to accept method references. This allows the test programs to be DRY-er as the inputs to the method under test don't have to be repeated. The float test method were not updated due to limitations in type inference if both float and double methods with functional interface parameters are present.
> 
> Also did some general tidying up for the test code.

Joe Darcy 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 six additional commits since the last revision:

 - Use consistent syntax for main method.
 - Merge branch 'master' into JDK-8270476
 - Appease jcheck.
 - Further refactoring.
 - Update copyright year, remove author tags.
 - JDK-8270476: Make floating-point test infrastructure more lambda and method reference friendly

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/7216/files
  - new: https://git.openjdk.java.net/jdk/pull/7216/files/e040a8ea..789782ce

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=7216&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=7216&range=00-01

  Stats: 2042 lines in 266 files changed: 1058 ins; 227 del; 757 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7216.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7216/head:pull/7216

PR: https://git.openjdk.java.net/jdk/pull/7216