RFR: 8314166: Update googletest to v1.14.0 [v2]

[Mikael Vidstedt]

> As part of the ongoing work to enable -Wconversion with gcc there are a number of occurrences of code in the GoogleTest code itself which need fixing. These have been addressed in version 1.14.0 of GoogleTest. This change is picking up that version, adjusting the relevant build configuration files for GHA and Oracle builds.
> 
> Note: This change updates the documentation and configuration so that 1.14.0 is the minimum required version. Strictly speaking 1.14.0 is not required until -Wconversion is _actually_ enabled but since that is presumably just around the corner..
> 
> Testing: GHA, tier1-5 (still in progress)

Mikael Vidstedt 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 two additional commits since the last revision:

 - Merge branch 'master' into 8314166-gtest-1.14.0
 - Update googletest to v1.14.0

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/15253/files
  - new: https://git.openjdk.org/jdk/pull/15253/files/36217d9e..acd7ec37

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15253&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15253&range=00-01

  Stats: 6213 lines in 224 files changed: 3185 ins; 398 del; 2630 mod
  Patch: https://git.openjdk.org/jdk/pull/15253.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15253/head:pull/15253

PR: https://git.openjdk.org/jdk/pull/15253